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Tian H, Sheraz née Rabbani S, Vickerman JC, Winograd N. Multiomics Imaging Using High-Energy Water Gas Cluster Ion Beam Secondary Ion Mass Spectrometry [(H 2O) n-GCIB-SIMS] of Frozen-Hydrated Cells and Tissue. Anal Chem 2021; 93:7808-7814. [PMID: 34038090 PMCID: PMC8190772 DOI: 10.1021/acs.analchem.0c05210] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 04/05/2021] [Indexed: 11/29/2022]
Abstract
Integration of multiomics at the single-cell level allows the unambiguous dissecting of phenotypic heterogeneity at different states such as health, disease, and biomedical response. Imaging mass spectrometry holds the promise of being able to measure multiple types of biomolecules in parallel in the same cell. We have explored the possibility of using water gas cluster ion beam secondary ion mass spectrometry [(H2O)n-GCIB-SIMS] as an analytical tool for multiomics assay. (H2O)n-GCIB has been hailed as an ideal ionization source for biological sampling owing to the enhanced chemical sensitivity and reduced matrix effect. Taking advantage of 1 μm spatial resolution by using a high-energy beam system, we have clearly shown the enhancement of multiple intact biomolecules up to a few hundredfold in single cells. Coupled with the cryogenic sample preparation/measurement, the lipids and metabolites were imaged simultaneously within the cellular region, uncovering the pristine chemistry for integrated omics in the same sample. We have demonstrated that double-charged myelin protein fragments and single-charged multiple lipids and metabolites can be localized in the same cells/tissue with a single acquisition. Our exploration has also been extended to the capability of (H2O)n-GCIB in the generation of multiple charged peptides on protein standards. Frozen hydration combined with (H2O)n-GCIB provides the possibility of universal enhancement for the ionization of multiple bio-molecules, including peptides/proteins which has allowed "omics" to become feasible in the same sample using SIMS.
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Affiliation(s)
- Hua Tian
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | | | - John C. Vickerman
- Manchester
Institute of Biotechnology, University of
Manchester, Manchester M1 7DN, U.K.
| | - Nicholas Winograd
- Department
of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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2
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Sheraz S, Tian H, Vickerman JC, Blenkinsopp P, Winograd N, Cumpson P. Enhanced Ion Yields Using High Energy Water Cluster Beams for Secondary Ion Mass Spectrometry Analysis and Imaging. Anal Chem 2019; 91:9058-9068. [DOI: 10.1021/acs.analchem.9b01390] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Sadia Sheraz
- School of Mechanical and Systems Engineering, University of Newcastle, Newcastle NE1 7RU, United Kingdom
| | - Hua Tian
- Department of Chemistry, Pennsylvania State University, State College, Pennsylvania 16802, United States
| | - John C. Vickerman
- School of Mechanical and Systems Engineering, University of Newcastle, Newcastle NE1 7RU, United Kingdom
- Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, United Kingdom
| | | | - Nicholas Winograd
- Department of Chemistry, Pennsylvania State University, State College, Pennsylvania 16802, United States
| | - Peter Cumpson
- School of Mechanical and Systems Engineering, University of Newcastle, Newcastle NE1 7RU, United Kingdom
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Alnajeebi AM, Vickerman JC, Lockyer NP. The influence of polyatomic primary ion chemistry on matrix effects in secondary ion mass spectrometry analysis. Rapid Commun Mass Spectrom 2018; 32:1962-1970. [PMID: 30133034 DOI: 10.1002/rcm.8265] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/01/2018] [Accepted: 08/10/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE The application of mass spectrometry imaging techniques to determine two- (2D) and three- (3D) dimensional chemical distribution ideally provides uniform, high sensitivity to multiple components and reliable quantification. These criteria are typically not met due to variations in sensitivity due to the chemistry of the analyte and surrounding surface chemistry. Here we explore the influence of projectile beam chemistry and sample chemistry in time-of-flight secondary ion mass spectrometry (TOF-SIMS). To the authors' knowledge this is the first time the combined effects of projectile chemistry and sample environment on the quantitative determination of mixed samples have been systematically studied. METHODS Secondary ion yields of lipid and amino acid mixtures were measured under 20 keV C60 , Arn , and (H2 O)n cluster ion bombardment (n = 2000 or 4000) using TOF-SIMS. Ion suppression/enhancement effects were studied in dry sample films and in trehalose and water ice matrices. RESULTS The extent of the matrix effects and the secondary ion yield were found to depend on the chemistry of the primary ion beam and (for C60 , Arn ) on the nature of the sample matrix. Under (H2 O)n bombardment the sample matrix had negligible effect on the analysis. CONCLUSIONS Compared with C60 and Arn , water-containing cluster projectiles enhanced the sensitivity of TOF-SIMS determination of the chosen analytes and reduced the effect of signal suppression/enhancement in multicomponent samples and in different sample matrices. One possible explanation for this is that the (H2 O)4000 projectile initiates on impact a nanoscale matrix environment that is very similar to that in frozen-hydrated samples in terms of the resulting ionisation effects. The competition between analytes for protons and the effect of the sample matrix are reduced with water-containing cluster projectiles. These chemically reactive projectile beams have improved characteristics for quantitative chemical imaging by TOF-SIMS compared with their non-reactive counterparts.
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Affiliation(s)
- Afnan M Alnajeebi
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK
- School of Chemistry, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
| | - John C Vickerman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK
- School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
| | - Nicholas P Lockyer
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK
- School of Chemistry, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
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Yokoyama Y, Aoyagi S, Fujii M, Matsuo J, Fletcher JS, Lockyer NP, Vickerman JC, Passarelli MK, Havelund R, Seah MP. Peptide Fragmentation and Surface Structural Analysis by Means of ToF-SIMS Using Large Cluster Ion Sources. Anal Chem 2016; 88:3592-7. [PMID: 26916620 DOI: 10.1021/acs.analchem.5b04133] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptide or protein structural analysis is crucial for the evaluation of biochips and biodevices, therefore an analytical technique with the ability to detect and identify protein and peptide species directly from surfaces with high lateral resolution is required. In this report, the efficacy of ToF-SIMS to analyze and identify proteins directly from surfaces is evaluated. Although the physics governing the SIMS bombardment process precludes the ability for researchers to detect intact protein or larger peptides of greater than a few thousand mass unit directly, it is possible to obtain information on the partial structures of peptides or proteins using low energy per atom argon cluster ion beams. Large cluster ion beams, such as Ar clusters and C60 ion beams, produce spectra similar to those generated by tandem MS. The SIMS bombardment process also produces peptide fragment ions not detected by conventional MS/MS techniques. In order to clarify appropriate measurement conditions for peptide structural analysis, peptide fragmentation dependency on the energy of a primary ion beam and ToF-SIMS specific fragment ions are evaluated. It was found that the energy range approximately 6 ≤ E/n ≤ 10 eV/atom is most effective for peptide analysis based on peptide fragments and [M + H] ions. We also observed the cleaving of side chain moieties at extremely low-energy E/n ≤ 4 eV/atom.
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Affiliation(s)
- Yuta Yokoyama
- Department of Materials and Life Science, Seikei University , Tokyo 180-8633, Japan
| | - Satoka Aoyagi
- Department of Materials and Life Science, Seikei University , Tokyo 180-8633, Japan
| | - Makiko Fujii
- Quantum Science and Engineering Center, Kyoto University , Kyoto 611-0011, Japan
| | - Jiro Matsuo
- Quantum Science and Engineering Center, Kyoto University , Kyoto 611-0011, Japan
| | - John S Fletcher
- Chemistry and Molecular Biology, University of Gothenburg , 40530 Göteborg, Sweden
| | - Nicholas P Lockyer
- Manchester Institute of Biotechnology and School of Chemistry , Manchester, M13 9PL, United Kingdom
| | - John C Vickerman
- Manchester Institute of Biotechnology and School of Chemistry , Manchester, M13 9PL, United Kingdom
| | - Melissa K Passarelli
- Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom
| | - Rasmus Havelund
- Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom
| | - Martin P Seah
- Surface and Nanoanalysis, National Physical Laboratory , Teddington, Middlesex, TW11 0LW, United Kingdom
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5
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Razo IB, Sheraz SNR, Henderson A, Lockyer NP, Vickerman JC. Mass spectrometric imaging of brain tissue by time-of-flight secondary ion mass spectrometry--How do polyatomic primary beams C₆₀⁺, Ar₂₀₀₀⁺, water-doped Ar₂₀₀₀⁺ and (H₂O)₆₀₀₀⁺ compare? Rapid Commun Mass Spectrom 2015; 29:1851-62. [PMID: 26411506 PMCID: PMC4989468 DOI: 10.1002/rcm.7285] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 05/11/2023]
Abstract
RATIONALE To discover the degree to which water-containing cluster beams increase secondary ion yield and reduce the matrix effect in time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging of biological tissue. METHODS The positive SIMS ion yields from model compounds, mouse brain lipid extract and mouse brain tissue together with mouse brain images were compared using 20 keV C60(+), Ar2000(+), water-doped Ar2000(+) and pure (H2O)6000(+) primary beams. RESULTS Water-containing cluster beams where the beam energy per nucleon (E/nucleon) ≈ 0.2 eV are optimum for enhancing ion yields dependent on protonation. Ion yield enhancements over those observed using Ar2000(+) lie in the range 10 to >100 using the (H2 O)6000 (+) beam, while with water-doped (H2O)Ar2000(+) they lie in the 4 to 10 range. The two water-containing beams appear to be optimum for tissue imaging and show strong evidence of increasing yields from molecules that experience matrix suppression under other primary beams. CONCLUSIONS The application of water-containing primary beams is suggested for biological SIMS imaging applications, particularly if the beam energy can be raised to 40 keV or higher to further increase ion yield and enhance spatial resolution to ≤1 µm.
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Affiliation(s)
- Irma Berrueta Razo
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, M13 9PL, UK
- School of Chemistry, The University of Manchester, Manchester, UK
| | - Sadia née Rabbani Sheraz
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, M13 9PL, UK
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
| | - Alex Henderson
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, M13 9PL, UK
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
| | - Nicholas P Lockyer
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, M13 9PL, UK
- School of Chemistry, The University of Manchester, Manchester, UK
| | - John C Vickerman
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, M13 9PL, UK
- School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK
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Sheraz née Rabbani S, Berrueta Razo I, Kohn T, Lockyer NP, Vickerman JC. Enhancing Ion Yields in Time-of-Flight-Secondary Ion Mass Spectrometry: A Comparative Study of Argon and Water Cluster Primary Beams. Anal Chem 2015; 87:2367-74. [DOI: 10.1021/ac504191m] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sadia Sheraz née Rabbani
- Manchester
Institute of Biotechnology, The University of Manchester
, Manchester, U.K
- School
of Chemical Engineering and Analytical Science, The University of Manchester
, Manchester, U.K
| | - Irma Berrueta Razo
- Manchester
Institute of Biotechnology, The University of Manchester
, Manchester, U.K
- School
of Chemistry, The University of Manchester
, Manchester, U.K
| | - Taylor Kohn
- Manchester
Institute of Biotechnology, The University of Manchester
, Manchester, U.K
- School
of Chemical Engineering and Analytical Science, The University of Manchester
, Manchester, U.K
| | - Nicholas P. Lockyer
- Manchester
Institute of Biotechnology, The University of Manchester
, Manchester, U.K
- School
of Chemistry, The University of Manchester
, Manchester, U.K
| | - John C. Vickerman
- Manchester
Institute of Biotechnology, The University of Manchester
, Manchester, U.K
- School
of Chemical Engineering and Analytical Science, The University of Manchester
, Manchester, U.K
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7
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Berrueta Razo I, Sheraz S, Henderson A, Lockyer NP, Vickerman JC. Comparing C
60
+
and (H
2
O)
n
+
clusters for mouse brain tissue analysis. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Irma Berrueta Razo
- Manchester Institute of Biotechnology (MIB) The University of Manchester Manchester UK
| | - Sadia Sheraz
- Manchester Institute of Biotechnology (MIB) The University of Manchester Manchester UK
| | - Alex Henderson
- Manchester Institute of Biotechnology (MIB) The University of Manchester Manchester UK
| | - Nicholas P. Lockyer
- Manchester Institute of Biotechnology (MIB) The University of Manchester Manchester UK
| | - John C. Vickerman
- Manchester Institute of Biotechnology (MIB) The University of Manchester Manchester UK
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Kawashima T, Kurosawa T, Aoyagi S, Sheraz née Rabbani S, Fletcher JS, Futigami M, Lockyer NP, Vickerman JC. Examination of fragment ions of polystyrene in TOF-SIMS spectra using MS/MS. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5548] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Satoka Aoyagi
- Department of Material and Life Science; Seikei University; Musashino-shi Japan
| | | | - John S. Fletcher
- Department of Chemistry and Molecular Biology; University of Gothenburg; Gothenburg Sweden
| | | | - Nicholas P. Lockyer
- Manchester Institute of Biotechnology; University of Manchester; Manchester UK
| | - John C. Vickerman
- Manchester Institute of Biotechnology; University of Manchester; Manchester UK
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9
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Tian H, Fletcher JS, Thuret R, Henderson A, Papalopulu N, Vickerman JC, Lockyer NP. Spatiotemporal lipid profiling during early embryo development of Xenopus laevis using dynamic ToF-SIMS imaging. J Lipid Res 2014; 55:1970-80. [PMID: 24852167 DOI: 10.1194/jlr.d048660] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging has been used for the direct analysis of single intact Xenopus laevis embryo surfaces, locating multiple lipids during fertilization and the early embryo development stages with subcellular lateral resolution (∼4 μm). The method avoids the complicated sample preparation for lipid analysis of the embryos, which requires selective chemical extraction of a pool of samples and chromatographic separation, while preserving the spatial distribution of biological species. The results show ToF-SIMS is capable of profiling multiple components (e.g., glycerophosphocholine, SM, cholesterol, vitamin E, diacylglycerol, and triacylglycerol) in a single X. laevis embryo. We observe lipid remodeling during fertilization and early embryo development via time course sampling. The study also reveals the lipid distribution on the gamete fusion site. The methodology used in the study opens the possibility of studying developmental biology using high resolution imaging MS and of understanding the functional role of the biological molecules.
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Affiliation(s)
- Hua Tian
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - John S Fletcher
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Raphael Thuret
- Faculty of Life Science, University of Manchester, Manchester, UK
| | - Alex Henderson
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Nancy Papalopulu
- Faculty of Life Science, University of Manchester, Manchester, UK
| | - John C Vickerman
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - Nicholas P Lockyer
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester, UK
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10
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Aoyagi S, Fletcher JS, Sheraz S, Kawashima T, Berrueta Razo I, Henderson A, Lockyer NP, Vickerman JC. Peptide structural analysis using continuous Ar cluster and C60 ion beams. Anal Bioanal Chem 2013; 405:6621-8. [DOI: 10.1007/s00216-013-7139-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 06/06/2013] [Accepted: 06/11/2013] [Indexed: 12/01/2022]
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Sheraz née Rabbani S, Barber A, Fletcher JS, Lockyer NP, Vickerman JC. Enhancing secondary ion yields in time of flight-secondary ion mass spectrometry using water cluster primary beams. Anal Chem 2013; 85:5654-8. [PMID: 23718847 PMCID: PMC3686110 DOI: 10.1021/ac4013732] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Low secondary ion yields from organic
and biological molecules
are the principal limitation on the future exploitation of time of
flight-secondary ion mass spectrometry (TOF-SIMS) as a surface and
materials analysis technique. On the basis of the hypothesis that
increasing the density of water related fragments in the ion impact
zone would enhance proton mediated reactions, a prototype water cluster
ion beam has been developed using supersonic jet expansion methodologies
that enable ion yields using a 10 keV (H2O)1000+ beam to be compared with those obtained using a 10 keV
Ar1000+ beam. The ion yields from four standard
compounds, arginine, haloperidol, DPPC, and angiotensin II, have been
measured under static+ and high ion dose conditions. Ion yield enhancements
relative to the argon beam on the order of 10 or more have been observed
for all the compounds such that the molecular ion yield per a 1 μm
pixel can be as high as 20, relative to 0.05 under an argon beam.
The water beam has also been shown to partially lift the matrix effect
in a 1:10 mixture of haloperidol and dipalmitoylphosphatidylcholine
(DPPC) that suppresses the haloperidol signal. These results provide
encouragement that further developments of the water cluster beam
to higher energies and larger cluster sizes will provide the ion yield
enhancements necessary for the future development of TOF-SIMS.
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Affiliation(s)
- John S. Fletcher
- Manchester Institute
of Biotechnology, University of Manchester, Manchester M13 9PL, U.K
| | - John C. Vickerman
- Manchester Institute
of Biotechnology, University of Manchester, Manchester M13 9PL, U.K
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13
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Affiliation(s)
| | - Jimmy D. Moore
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street; Manchester; M1 7DN; UK
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Moore JD, Henderson A, Fletcher JS, Lockyer NP, Vickerman JC. Peak picking as a pre-processing technique for imaging time of flight secondary ion mass spectrometry. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.5062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jimmy D. Moore
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science; The University of Manchester; 131 Princess St. Manchester M1 7DN UK
| | - Alex Henderson
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science; The University of Manchester; 131 Princess St. Manchester M1 7DN UK
| | - John S. Fletcher
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science; The University of Manchester; 131 Princess St. Manchester M1 7DN UK
- Department of Chemistry and Molecular Biology; University of Gothenburg; 41296 Gothenburg Sweden
| | - Nicholas P. Lockyer
- Manchester Institute of Biotechnology, School of Chemistry; The University of Manchester; 131 Princess St. Manchester M1 7DN UK
| | - John C. Vickerman
- Manchester Institute of Biotechnology, School of Chemical Engineering and Analytical Science; The University of Manchester; 131 Princess St. Manchester M1 7DN UK
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15
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Armitage EG, Kotze HL, Fletcher JS, Henderson A, Williams KJ, Lockyer NP, Vickerman JC. Time-of-flight SIMS as a novel approach to unlocking the hypoxic properties of cancer. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.5050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Emily G Armitage
- Doctoral Training Centre for Integrative Systems Biology, School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre; University of Manchester; Manchester; M1 7DN; UK
| | - Helen L Kotze
- Doctoral Training Centre for Integrative Systems Biology, School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre; University of Manchester; Manchester; M1 7DN; UK
| | - John S Fletcher
- Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre; University of Manchester; Manchester; M1 7DN; UK
| | - Alex Henderson
- Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre; University of Manchester; Manchester; M1 7DN; UK
| | - Kaye J Williams
- School of Pharmacy and Pharmaceutical Sciences; University of Manchester; Oxford Road; Manchester; M13 9PT; UK
| | - Nicholas P Lockyer
- School of Chemistry; University of Manchester; Oxford Road; Manchester; M13 9PL; UK
| | - John C Vickerman
- Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre; University of Manchester; Manchester; M1 7DN; UK
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16
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Longobardo A, Macpherson AN, Vickerman JC, Lockyer NP. New prospects for molecular post-ionisation using femtosecond IR lasers. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.4951] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alessia Longobardo
- Manchester Interdisciplinary Biocentre & School of Chemical Engineering and Analytical Science; University of Manchester; 131 Princess Street Manchester M13 9PL UK
- Photon Science Institute, School of Chemistry; University of Manchester; Manchester M13 9PL UK
| | - Alisdair N. Macpherson
- Photon Science Institute, School of Chemistry; University of Manchester; Manchester M13 9PL UK
| | - John C. Vickerman
- Manchester Interdisciplinary Biocentre & School of Chemical Engineering and Analytical Science; University of Manchester; 131 Princess Street Manchester M13 9PL UK
| | - Nicholas P. Lockyer
- Photon Science Institute, School of Chemistry; University of Manchester; Manchester M13 9PL UK
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17
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Fletcher JS, Rabbani S, Barber AM, Lockyer NP, Vickerman JC. Comparison of C60and GCIB primary ion beams for the analysis of cancer cells and tumour sections. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.4874] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- John S. Fletcher
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science; University of Manchester; Manchester; M13 9PL; UK
| | - Sadia Rabbani
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science; University of Manchester; Manchester; M13 9PL; UK
| | | | - Nicholas P. Lockyer
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science; University of Manchester; Manchester; M13 9PL; UK
| | - John C. Vickerman
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science; University of Manchester; Manchester; M13 9PL; UK
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18
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Fletcher JS, Vickerman JC, Winograd N. Label free biochemical 2D and 3D imaging using secondary ion mass spectrometry. Curr Opin Chem Biol 2011; 15:733-40. [PMID: 21664172 DOI: 10.1016/j.cbpa.2011.05.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 05/19/2011] [Accepted: 05/20/2011] [Indexed: 11/24/2022]
Abstract
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides a method for the detection of native and exogenous compounds in biological samples on a cellular scale. Through the development of novel ion beams the amount of molecular signal available from the sample surface has been increased. Through the introduction of polyatomic ion beams, particularly C(60), ToF-SIMS can now be used to monitor molecular signals as a function of depth as the sample is eroded thus proving the ability to generate 3D molecular images. Here we describe how this new capability has led to the development of novel instrumentation for 3D molecular imaging while also highlighting the importance of sample preparation and discuss the challenges that still need to be overcome to maximise the impact of the technique.
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Affiliation(s)
- John S Fletcher
- School of Chemical Engineering and Analytical Science, Manchester Interdisciplinary Biocentre, University of Manchester, Manchester M1 7DN, UK.
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Abstract
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an established technique for the characterization of solid sample surfaces. The introduction of polyatomic ion beams, such as C(60), has provided the associated ability to perform molecular depth-profiling and 3D molecular imaging. However, not all samples perform equally under C(60) bombardment, and it is probably naïve to think that there will be an ion beam that will be applicable in all situations. It is therefore important to explore the potential of other candidates. A systematic study of the suitability of argon gas cluster ion beams (Ar-GCIBs) of general composition Ar(n)(+), where n = 60-3000, as primary particles in TOF-SIMS analysis has been performed. We have assessed the potential of the Ar-GCIBs for molecular depth-profiling in terms of damage accumulation and sputter rate and also as analysis beams where spectral quality and secondary ion yields are considered. We present results with direct comparison with C(60) ions on the same sample in the same instrument on polymer, polymer additive, and biomolecular samples, including lipids and small peptides. Large argon clusters show reduced damage accumulation compared with C(60) with an approximately constant sputter rate as a function of Ar cluster size. Further, on some samples, large argon clusters produce changes in the mass spectra indicative of a more gentle ejection mechanism. However, there also appears to be a reduction in the ionization of secondary species as the size of the Ar cluster increases.
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Affiliation(s)
- Sadia Rabbani
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester, M13 9PL, UK
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Fletcher JS, Rabbani S, Henderson A, Lockyer NP, Vickerman JC. Three-dimensional mass spectral imaging of HeLa-M cells--sample preparation, data interpretation and visualisation. Rapid Commun Mass Spectrom 2011; 25:925-932. [PMID: 21416529 DOI: 10.1002/rcm.4944] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 01/13/2011] [Accepted: 01/13/2011] [Indexed: 05/30/2023]
Abstract
Time-of-flight secondary ion mass spectrometry (ToFSIMS) is being applied increasingly to the study of biological systems where the chemical specificity of mass spectrometry and the high lateral resolution imaging capabilities can be exploited. Here we report a comparison of two cell sample preparation methods and demonstrate how they influence the outcome of the ToFSIMS analysis for three-dimensional (3D) imaging of biological cells using our novel buncher-ToF instrument (J105 3D Chemical Imager) equipped with a C(60) primary ion beam. Cells were analysed fixed and freeze-dried and non-fixed, frozen-hydrated. It is concluded that maintaining the cells in a non-fixed frozen-hydrated state during the analysis helps reduce chemical redistribution, producing cleaner spectra and improved chemical contrast in both 2D and 3D imaging. Insights into data interpretation are included and we present methods for 3D reconstruction of the data using multivariate analysis techniques.
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Affiliation(s)
- John S Fletcher
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
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Fletcher JS, Lockyer NP, Vickerman JC. Developments in molecular SIMS depth profiling and 3D imaging of biological systems using polyatomic primary ions. Mass Spectrom Rev 2011; 30:142-74. [PMID: 20077559 DOI: 10.1002/mas.20275] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In principle mass spectral imaging has enormous potential for discovery applications in biology. The chemical specificity of mass spectrometry combined with spatial analysis capabilities of liquid metal cluster beams and the high yields of polyatomic ion beams should present unprecedented ability to spatially locate molecular chemistry in the 100 nm range. However, although metal cluster ion beams have greatly increased yields in the m/z range up to 1000, they still have to be operated under the static limit and even in most favorable cases maximum yields for molecular species from 1 µm pixels are frequently below 20 counts. However, some very impressive molecular imaging analysis has been accomplished under these conditions. Nevertheless although molecular ions of lipids have been detected and correlation with biology is obtained, signal levels are such that lateral resolution must be sacrificed to provide a sufficient signal to image. To obtain useful spatial resolution detection below 1 µm is almost impossible. Too few ions are generated! The review shows that the application of polyatomic primary ions with their low damage cross-sections offers hope of a new approach to molecular SIMS imaging by accessing voxels rather than pixels to thereby increase the dynamic signal range in 2D imaging and to extend the analysis to depth profiling and 3D imaging. Recent data on cells and tissue analysis suggest that there is, in consequence, the prospect that a wider chemistry might be accessible within a sub-micron area and as a function of depth. However, these advances are compromised by the pulsed nature of current ToF-SIMS instruments. The duty cycle is very low and results in excessive analysis times, and maximum mass resolution is incompatible with maximum spatial resolution. New instrumental directions are described that enable a dc primary beam to be used that promises to be able to take full advantage of all the capabilities of the polyatomic ion beam. Some new data are presented that suggest that the aspirations for these new instruments will be realized. However, although prospects are good, the review highlights the continuing challenges presented by the low ionization efficiency and the complications that arise from matrix effects.
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Affiliation(s)
- John S Fletcher
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M60 1QD, UK
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Piwowar AM, Fletcher JS, Kordys J, Lockyer NP, Winograd N, Vickerman JC. Effects of Cryogenic Sample Analysis on Molecular Depth Profiles with TOF-Secondary Ion Mass Spectrometry. Anal Chem 2010; 82:8291-9. [DOI: 10.1021/ac101746h] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alan M. Piwowar
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - John S. Fletcher
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Jeanette Kordys
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Nicholas P. Lockyer
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Nicholas Winograd
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - John C. Vickerman
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, United Kingdom
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Lanekoff I, Kurczy ME, Hill R, Fletcher JS, Vickerman JC, Winograd N, Sjövall P, Ewing AG. Time of flight mass spectrometry imaging of samples fractured in situ with a spring-loaded trap system. Anal Chem 2010; 82:6652-9. [PMID: 20593800 PMCID: PMC2922971 DOI: 10.1021/ac101243b] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An in situ freeze fracture device featuring a spring-loaded trap system has been designed and characterized for time of flight secondary ion mass spectrometry (TOF SIMS) analysis of single cells. The device employs the sandwich assembly, which is typically used in freeze fracture TOF SIMS experiments to prepare frozen, hydrated cells for high-resolution SIMS imaging. The addition of the spring-loaded trap system to the sandwich assembly offers two advances to this sample preparation method. First, mechanizing the fracture by adding a spring standardizes each fracture by removing the need to manually remove the top of the sandwich assembly with a cryogenically cooled knife. A second advance is brought about because the top of the sandwich is not discarded after the sandwich assembly has been fractured. This results in two imaging surfaces effectively doubling the sample size and providing the unique ability to image both sections of a cell bifurcated by the fracture. Here, we report TOF SIMS analysis of freeze fractured rat pheochromocytoma (PC12) cells using a Bi cluster ion source. This work exhibits the ability to obtain single cell chemical images with subcellular lateral resolution from cells preserved in an ice matrix. In addition to preserving the cells, the signal from lipid fragment ions rarely identified in single cells are better observed in the freeze-fractured samples for these experiments. Furthermore, using the accepted argument that K(+) signal indicates a cell that has been fractured though the cytoplasm, we have also identified different fracture planes of cells over the surface. Coupling a mechanized freeze fracture device to high-resolution cluster SIMS imaging will provide the sensitivity and resolution as well as the number of trials required to carry out biologically relevant SIMS experiments.
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Affiliation(s)
- Ingela Lanekoff
- Department of Chemistry, University of Gothenburg, SE-41296, Göteborg, Sweden
| | - Michael E. Kurczy
- Department of Chemistry, 104 Chemistry Research Building, The Pennsylvania State University, University Park, PA USA 16802
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Rowland Hill
- Ionoptika Ltd, Unit 7, Warrior Park, Eagle Close, Chandlers Ford, Hampshire, SO53 4NF, UK
| | | | | | - Nick Winograd
- Department of Chemistry, 104 Chemistry Research Building, The Pennsylvania State University, University Park, PA USA 16802
| | - Peter Sjövall
- Chemistry and Materials Technology, SP Technical Research Institute of Sweden, Borås, Sweden
| | - Andrew G. Ewing
- Department of Chemistry, University of Gothenburg, SE-41296, Göteborg, Sweden
- Department of Chemistry, 104 Chemistry Research Building, The Pennsylvania State University, University Park, PA USA 16802
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Reichenbach SE, Tian X, Lindquist R, Tao Q, Henderson A, Vickerman JC. Interactive spatio-spectral analysis of three-dimensional mass-spectral (3DxMS) chemical images. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Webb RP, Garrison BJ, Vickerman JC. The effect of the H:C ratio on the sputtering of molecular solids by fullerenes. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3421] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Fletcher JS, Lockyer NP, Vickerman JC. Molecular SIMS imaging; spatial resolution and molecular sensitivity: have we reached the end of the road? Is there light at the end of the tunnel? SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3488] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Conlan XA, Baker MJ, Krieg R, Lockyer NP, Vickerman JC, Barnett NW, Lim KF. Insight into the swelling mechanism involved in the recovery of serial numbers erased from polymer surfaces. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3510] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Klerk LA, Lockyer NP, Kharchenko A, MacAleese L, Dankers PYW, Vickerman JC, Heeren RMA. C60+ Secondary Ion Microscopy Using a Delay Line Detector. Anal Chem 2009; 82:801-7. [DOI: 10.1021/ac902587g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Leendert A. Klerk
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Nicholas P. Lockyer
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Andriy Kharchenko
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Luke MacAleese
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Patricia Y. W. Dankers
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - John C. Vickerman
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Ron M. A. Heeren
- FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG, Amsterdam, Netherlands, Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom, and Department of Pathology and Medical Biology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
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Fletcher JS, Vickerman JC. A new SIMS paradigm for 2D and 3D molecular imaging of bio-systems. Anal Bioanal Chem 2009; 396:85-104. [PMID: 19669735 DOI: 10.1007/s00216-009-2986-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 07/13/2009] [Indexed: 11/28/2022]
Abstract
With the implementation of focused primary ion beams, secondary ion mass spectrometry (SIMS) has become a significant technique in the rapidly emerging field of mass spectral imaging in the biological sciences. Liquid metal ion guns (LMIG) offered the prospect of sub-100 nm spatial resolution, however this aspiration has yet to be reached for molecular imaging. This brief review shows that using LMIG the limitations of the static limit and low ionization probability will restrict useful imaging to around 2 mum spatial resolution with high-yield molecules. The only prospect of going beyond this in the absence of factors of 100 increase in ionization probability is to use polyatomic ion beams such as C (60) (+) , for which bombardment induced damage is low. In these cases sub-micron imaging becomes possible, using voxels together with molecular depth profiling and 3D imaging. The discussion shows that conventional ToF-SIMS instrumentation then becomes a limitation in that the pulsed ion beam has a very low duty cycle which results in inordinately long analysis times, and pulsing the beam means that high-mass resolution and high spatial resolution are mutually incompatible. New instrumental configurations are described that allow the use of a dc ion beam and separate the mass spectrometry for the ion formation process. Early results from these instruments suggest that sub-micron analysis and imaging with high mass resolution and good ion yields are now realizable, although the low ion yield issue still needs to be solved.
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Affiliation(s)
- John S Fletcher
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M1 7DN, UK
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Abstract
The early stages of C(60) bombardment of octane and octatetraene crystals are modeled using molecular dynamics simulations with incident energies of 5-20 keV. Using the AIREBO potential, which allows for chemical reactions in hydrocarbon molecules, we are able to investigate how the projectile energy is partitioned into changes in potential and kinetic energy as well as how much energy flows into reacted molecules and internal energy. Several animations have been included to illustrate the bombardment process. The results show that the material near the edge of the crater can be ejected with low internal energies and that ejected molecules maintain their internal energies in the plume, in contrast to a collisional cooling mechanism previously proposed. In addition, a single C(60) bombardment was able to create many free and reacted H atoms which may aid in the ionization of molecules upon subsequent bombardment events.
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Affiliation(s)
- Barbara J Garrison
- Department of Chemistry, 104 Chemistry Building, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Piwowar AM, Lockyer NP, Vickerman JC. Salt effects on ion formation in desorption mass spectrometry: an investigation into the role of alkali chlorides on peak suppression in time-of-flight-secondary ion mass spectrometry. Anal Chem 2009; 81:1040-8. [PMID: 19125566 DOI: 10.1021/ac8020888] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In secondary ion mass spectrometry, the molecular environment from which a sample is analyzed can influence ion formation, affecting the resulting data. With the recent surge in studies involving examination of biological specimens, a better understanding of constituents commonly found in biological matrixes is necessary. In this article we discuss results from an investigation directed at understanding the role of salts doped as alkali chlorides in a model biological environment, arginine. The data show that addition of salt to the model system causes ion suppression of all the major mass spectral peaks attributed to arginine, with KCl having the largest suppression effect. Potential causes for the suppression effects are briefly discussed in relation to collected data. These theories include sample degradation, formation of salt adduct peaks, and anion neutralization. Investigation of the arginine salt data in comparison with data collected from pure salt systems indicates that suppression of the positive secondary ions is likely caused by a neutralization process involving the salt counteranion, chloride. To address the suppression issue, various procedures were performed on the arginine films such as sample washing with a cleaning solution (ammonium formate, ethanol, water) and analysis of films in a frozen-hydrated state. We present data from the analysis of the frozen-hydrated samples that shows both an ion yield enhancement and a significant amelioration of the salt suppression effects when compared to the samples run under standard conditions, demonstrating that it is a helpful approach to dealing with salt suppression.
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Affiliation(s)
- Alan M Piwowar
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, The University of Manchester, Manchester M1 7DN, United Kingdom.
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34
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Vaidyanathan S, Fletcher JS, Jarvis RM, Henderson A, Lockyer NP, Goodacre R, Vickerman JC. Explanatory multivariate analysis of ToF-SIMS spectra for the discrimination of bacterial isolates. Analyst 2009; 134:2352-60. [DOI: 10.1039/b907570d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Fletcher JS, Rabbani S, Henderson A, Blenkinsopp P, Thompson SP, Lockyer NP, Vickerman JC. A New Dynamic in Mass Spectral Imaging of Single Biological Cells. Anal Chem 2008; 80:9058-64. [DOI: 10.1021/ac8015278] [Citation(s) in RCA: 225] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John S. Fletcher
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - Sadia Rabbani
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - Alex Henderson
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - Paul Blenkinsopp
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - Steve P. Thompson
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - Nicholas P. Lockyer
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
| | - John C. Vickerman
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., Ionoptika Ltd., Southampton. U.K., and Scientific Analysis Instruments, Manchester, U.K
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Baker MJ, Zheng L, Winograd N, Lockyer NP, Vickerman JC. Mass spectral imaging of glycophospholipids, cholesterol, and glycophorin a in model cell membranes. Langmuir 2008; 24:11803-11810. [PMID: 18788765 PMCID: PMC2601567 DOI: 10.1021/la802582f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Time of flight secondary ion mass spectrometry (ToF-SIMS) and the Langmuir-Blodgett (LB) technique have been used to create and analyze reproducible membrane mimics of the inner and outer leaflets of a cellular membrane to investigate lipid-protein and lipid-lipid interactions. Films composed of phospholipids, cholesterol and an integral membrane protein were utilized. The results show the outer membrane leaflet mimic (DPPC/cholesterol/glycophorin A LB film) consisting of a single homogeneous phase whereas the inner membrane leaflet mimic (DPPE/cholesterol/glycophorin A LB film) displays heterogeneity in the form of two separate phases. A DPPE/cholesterol phase and a glycophorin A phase. This points to differences in membrane domain formation based upon the different chemical composition of the leaflets of a cell membrane. The reliability of the measurements was enhanced by establishing the influence of the matrix effect upon the measurement and by utlilizing PCA to enhance the contrast of the images.
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Affiliation(s)
- Matthew J Baker
- Manchester Interdisciplinary Biocentre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M1 7DN, U.K.
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Vaidyanathan S, Fletcher JS, Goodacre R, Lockyer NP, Micklefield J, Vickerman JC. Subsurface Biomolecular Imaging of Streptomyces coelicolor Using Secondary Ion Mass Spectrometry. Anal Chem 2008; 80:1942-51. [DOI: 10.1021/ac701921e] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Seetharaman Vaidyanathan
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - John S. Fletcher
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Roy Goodacre
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Nicholas P. Lockyer
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Jason Micklefield
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - John C. Vickerman
- School of Chemical Engineering and Analytical Sciences, and School of Chemistry, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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Abstract
In this paper, the effect of prolonged C60(+) primary ion bombardment on the chemical information available from a section of rat brain is discussed. Initial attempts demonstrate the rapid loss of molecular signal from the bombarded area with both C60(+) and Au(+) used as a monatomic comparison. However, the nature of this signal disappearance is shown to be different. Analysis of the C60(+) data indicates a correlation between signal loss and the appearance of sodium and potassium adducts of phosphate and protein fragments; this is supported by model systems. By using an ammonium formate wash to reduce the salt levels within the tissue this effect is removed, allowing the chemistry of the tissue section to be better probed. Results collected from multiple sections suggest that at room temperature under vacuum conditions there is a migration of lipids to the surface of the tissue. Three-dimensional (3D) imaging is used to demonstrate that once these lipids are removed other species, such as proteins, are uncovered. By depth profiling the sample in a frozen state, the degree and importance of lipid migration to the observed localization of native compounds is assessed. This investigation into the behavior of biological tissue under high C60(+) fluxes not only allows an evaluation of the potential accuracy of 3D SIMS mapping of important biological molecules but also demonstrates the possibility of using ion doses beyond the traditional "static limit" to provide higher secondary ion yields that could lead to greater detection limits and smaller useful lateral resolution within such analyses.
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Affiliation(s)
- Emrys A Jones
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom.
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Baker MJ, Brown MD, Gazi E, Clarke NW, Vickerman JC, Lockyer NP. Discrimination of prostate cancer cells and non-malignant cells using secondary ion mass spectrometry. Analyst 2007; 133:175-9. [PMID: 18227938 DOI: 10.1039/b712853c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This communication utilises Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) combined with multivariate analysis to obtain spectra from the surfaces of three closely related cell lines allowing their discrimination based upon mass spectral ions.
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Affiliation(s)
- Matthew J Baker
- Manchester Interdisciplinary Biocentre, Centre for Instrumentation and Analytical Science, School of Chemical Engineering and Analytical Science, The University of Manchester, UK.
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40
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Biddulph GX, Piwowar AM, Fletcher JS, Lockyer NP, Vickerman JC. Properties of C84 and C24H12 molecular ion sources for routine TOF-SIMS analysis. Anal Chem 2007; 79:7259-66. [PMID: 17822312 DOI: 10.1021/ac071442x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C84+ and coronene (C24H12+) have been studied as primary ions for use in secondary ion mass spectrometry. A representative range of samples has been used to compare the effectiveness of each primary ion with the existing C60+, Au+, and Au3+ primary ions. It was found that C84 is the most effective primary ion providing higher secondary ion yields and a high molecular to fragment ion ratio. Coronene had a performance similar to C60. Coronene and C60 primary ions were also used to extend a previous study of matrix suppression/enhancement effects. The C60 was found to ameliorate this effect, possibly due to the increase in protonation in polyatomic sputtering, and coronene was found to further reduce suppression showing evidence of a chemical effect.
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Affiliation(s)
- Gregory X Biddulph
- Manchester Interdisciplinary Biocentre, University of Manchester, Manchester, M1 7DN, UK
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Jones EA, Lockyer NP, Kordys J, Vickerman JC. Suppression and enhancement of secondary ion formation due to the chemical environment in static-secondary ion mass spectrometry. J Am Soc Mass Spectrom 2007; 18:1559-67. [PMID: 17604641 DOI: 10.1016/j.jasms.2007.05.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 05/09/2007] [Accepted: 05/20/2007] [Indexed: 05/16/2023]
Abstract
Through analyzing mixtures of compounds of known gas-phase basicities, the importance of this property on the secondary ions emitted from a surface under primary ion bombardment is investigated. The aim is to obtain a greater understanding of the ionization mechanisms that occur in secondary ion mass spectrometry (SIMS). The commonly used matrix assisted laser desorption/ionization (MALDI) matrix 2,4,6-trihydroxyacetophenone (THAP) and a range of low molecular weight biomolecules were used to investigate whether analyte/matrix suppression effects that have been observed in analogous MALDI experiments were also present in static-SIMS. The outcome of the experiments demonstrates that strong suppression of the quasi-molecular signal of one molecule in a mixture can occur due to the presence of the other, with the gas-phase basicity of the compounds being a good indicator of the secondary ions detected. It is also demonstrated that the suppression of the quasi-molecular ion signal of a compound in a two-component mixture can be minimized by the inclusion of a third compound of suitable gas-phase basicity.
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Affiliation(s)
- Emrys A Jones
- Surface Analysis Research Centre, Manchester Interdisciplinary Biocentre, CEAS, University of Manchester, Manchester, United Kingdom.
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Fletcher JS, Conlan XA, Jones EA, Biddulph G, Lockyer NP, Vickerman JC. TOF-SIMS analysis using C60. Effect of impact energy on yield and damage. Anal Chem 2007; 78:1827-31. [PMID: 16536417 DOI: 10.1021/ac051624w] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C60 has been shown to give increased sputter yields and, hence, secondary ions when used as a primary particle in SIMS analysis. In addition, for many samples, there is also a reduction in damage accumulation following continued bombardment with the ion beam. In this paper, we report a study of the impact energy (up to 120 keV) of C60 on the secondary ion yield from a number of samples with consideration of any variation in yield response over mass ranges up to m/z 2000. Although increased impact energy is expected to produce a corresponding increase in sputter yield/rate, it is important to investigate any increase in sample damage with increasing energy and, hence, efficiency of the ion beams. On our test samples including a metal, along with organic samples, there is a general increase in secondary ion yield of high-mass species with increasing impact energy. A corresponding reduction in the formation of low-mass fragments is also observed. Depth profiling of organic samples demonstrates that when using C60, there does not appear to be any increase in damage evident in the mass spectra as the impact energy is increased.
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Affiliation(s)
- John S Fletcher
- Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M60 1QD, UK.
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Fletcher JS, Lockyer NP, Vaidyanathan S, Vickerman JC. TOF-SIMS 3D Biomolecular Imaging ofXenopuslaevisOocytes Using Buckminsterfullerene (C60) Primary Ions. Anal Chem 2007; 79:2199-206. [PMID: 17302385 DOI: 10.1021/ac061370u] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) using buckminsterfullerene (C60) as the primary ion source has the ability to generate chemical images of surfaces with high sensitivities and minimal chemical damage. We studied the application of C60+ to depth profile a biological cell surface in a controlled manner and to subsequently image the revealed subsurfaces, in order to generate three-dimensional molecular images of the biological system. Such an analytical tool not only enables the surface localization of molecular species to be mapped but also enables the biomolecular distribution as a function of depth to be investigated with minimal sample preparation/intervention. Here we demonstrate the technique with a freeze-dried Xenopus laevis oocyte, which is a single cell. A C60+ ion beam was used with computer-controlled analyses and etch cycles. Mass spectra derived from the surface revealed peaks corresponding to cholesterol (m/z 369) and other lipids at m/z 540-570 and 800-1000, in the positive ion mode, and lipid fatty acid side chains (e.g., m/z 255) in the negative ion mode. To our knowledge, this is the first demonstration of the 3D biomolecular imaging within an actual biological system using TOF-SIMS.
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Affiliation(s)
- John S Fletcher
- Manchester Interdisciplinary Biocentre, Centre for Instrumentation and Analytical Science, School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M1 7ND, UK. John.Fletcher@ manchester.ac.uk
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Jungnickel H, Jones EA, Lockyer NP, Oliver SG, Stephens GM, Vickerman JC. Application of TOF-SIMS with chemometrics to discriminate between four different yeast strains from the species Candida glabrata and Saccharomyces cerevisiae. Anal Chem 2007; 77:1740-5. [PMID: 15762580 DOI: 10.1021/ac048792t] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a TOF-SIMS analysis of the cell surface differences between four yeast strains from two species, Candida glabrata and Saccharomyces cerevisiae (haploid strains BY4742 and BY4741 and the derived diploid BY4743). The study assesses the suitability of TOF-SIMS analysis in combination with statistical methods (principal component analysis, Fisher's discriminant analysis, and cluster analysis) for the discrimination between the four yeast strains. We demonstrate that a combination of these statistical methods identifies 34 ions, from a total data set of 1200, which can be used to distinguish between the four yeasts. The study discusses the assignments of surface cell membrane phospholipids for the identified ions and the resulting differences in the phospholipid pattern between the four yeasts, particularly in relation to ploidy and budding pattern. The method shows that fatty acids, phosphatidylglycerols, phosphatidylethanolamines, phosphatidylserines, and phosphatidylcholines, as well as cardiolipins, are of diagnostic importance.
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Affiliation(s)
- H Jungnickel
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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Conlan XA, Lockyer NP, Vickerman JC. Is proton cationization promoted by polyatomic primary ion bombardment during time-of-flight secondary ion mass spectrometry analysis of frozen aqueous solutions? Rapid Commun Mass Spectrom 2006; 20:1327-34. [PMID: 16555365 DOI: 10.1002/rcm.2446] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ion bombardment of pure water ice by Au+ monoatomic and Au3 + and C60 + polyatomic projectiles results in the emission of two series of water cluster ions-(H2O)n + and (H2O)nH+-with n ranging from 1 to >40. The cluster ion yields are very significantly higher under polyatomic ion bombardment than when using an Au+ primary ion. The yield of the protonated water species (H2O)nH+ is found to be enhanced by increasing ion fluence. C60 + bombardment results in a very dramatic increase in the (H2O)nH+ yield and decrease in the yield of (H2O)n +. Au3 + also significantly increased the yield of protonated species relative to the non-protonated but to a lesser extent than C60 +. Bombardment by Au+ also increased the yield of protonated species but to a very much smaller extent. The hypothesis that the protonated species may enhance the yield of [M+H]+ from solute molecules in solution has been investigated using two amino acids, alanine and arginine, and a nucleic base, adenine. The data suggest that the protons produced by the sputtering of water ice are depleted in the presence of these solutes and concurrently the yields of solute-related [M+H]+ and immonium secondary ions are greatly enhanced. These yield enhancements are analysed in the light of other possible contributors such as increased rates of sputtering under polyatomic beams and increased secondary ion yields as a consequence of solute dispersion. It is concluded that enhanced proton attachment is occurring in polyatomic sputtered frozen aqueous solutions.
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Affiliation(s)
- Xavier A Conlan
- Surface Analysis Research Centre, School of Chemical Engineering and Analytical Science, The University of Manchester, P.O. Box 88, Manchester M60 1QD, UK
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Wong SCC, Lockyer NP, Vickerman JC. Mechanisms of secondary ion emission from self-assembled monolayers and multilayers. SURF INTERFACE ANAL 2005. [DOI: 10.1002/sia.2069] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gazi E, Dwyer J, Lockyer N, Gardner P, Vickerman JC, Miyan J, Hart CA, Brown M, Shanks JH, Clarke N. The combined application of FTIR microspectroscopy and ToF-SIMS imaging in the study of prostate cancer. Faraday Discuss 2004; 126:41-59; discussion 77-92. [PMID: 14992399 DOI: 10.1039/b304883g] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
At present. a prognosis for prostate cancer (CaP) is determined by its accurate assessment of disease grade and stage. Histopathological typing using the Gleason grading system is the most universally accepted approach for grading CaP and provides an indication as to the aggressiveness of the tumour at the time of presentation. However, this system is based upon a visual criterion of pattern recognition that is operator dependent and subject to intra- and inter-observer variability, which can result in inappropriate patient management. Thus, there is a need for a molecular based diagnostic technique to grade tissue samples in a reliable and reproducible manner. In this paper we report a prototype diagnostic classifier for Gleason graded CaP tissue, based upon the integration of FTIR microspectroscopy with linear discriminant analysis (LDA). Blind testing of this model demonstrates 80% agreement of FTIR-LDA grade to histology, for the specimens analysed. We also study the effects of connective tissue absorption upon the area ratio of peaks at A1030 cm(-1)/A1080(cm(-1) which we use as a criterion to biospectroscopically map and distinguish areas of benign from malignant tissue. In addition, imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been applied to study freeze-dried, freeze-fractured prostate cancer cells in vitro. Preliminary results demonstrate localisation of various species including K, Ca and Mg within the cytoplasm that are present at millimolar concentrations and vital to cell physiology. The soft ionisation technique employed also permits for molecular information to be obtained and this has been used to evaluate chemically, different fracture planes within the analysis area.
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Affiliation(s)
- Ehsan Gazi
- Department of Chemistry, UMIST, Manchester, UK M60 1QD
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Affiliation(s)
- John S. Fletcher
- Department of Chemistry, UMIST, Sackville St. Manchester M60 1QD, United Kingdom and Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Alex Henderson
- Department of Chemistry, UMIST, Sackville St. Manchester M60 1QD, United Kingdom and Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Andrew B. Horn
- Department of Chemistry, UMIST, Sackville St. Manchester M60 1QD, United Kingdom and Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - John C. Vickerman
- Department of Chemistry, UMIST, Sackville St. Manchester M60 1QD, United Kingdom and Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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Couling SB, Nash KL, Fletcher J, Henderson A, Vickerman JC, Horn AB. Identification of surface molecular hydrates on solid sulfuric acid films. J Am Chem Soc 2003; 125:13038-9. [PMID: 14570472 DOI: 10.1021/ja036384l] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Infrared spectroscopic and secondary ion mass spectrometric studies reveal the presence of a stable molecular hydrate on the surface of condensed thin films of ionic sulfuric acid hydrates. This surface species is observed to play a role in the interaction of ammonia, reacting rapidly until the material is depleted. A slower, continuous process is also observed, attributed to a diffusion-limited reaction between incoming NH3 and H3O+ located at or near the surface.
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Affiliation(s)
- Suzanne B Couling
- Department of Chemistry, University of York, Heslington, York YO1 5DD, UK
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