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Wu Q, Cao F, Wang H, Kou J, Zhang Z, Yang X. Promoted Hole Transport Capability by Improving Lateral Current Spreading for High-Efficiency Quantum Dot Light-Emitting Diodes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001760. [PMID: 33304749 PMCID: PMC7709982 DOI: 10.1002/advs.202001760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/28/2020] [Indexed: 06/12/2023]
Abstract
Carrier imbalance resulting from stronger electron injection from ZnO into quantum-dot (QD) emissive layer than hole injection is one critical issue that constrains the performance of QDs-based light-emitting diodes (QLEDs). This study reports highly efficient inverted QLEDs enabled by periodic insertion of MoO3 into (4,4'-bis(N-carbazolyl)-1,1'-biphenyl) (CBP) hole transport layer (HTL). The periodic ultrathin MoO3/CBP-stacked HTL results in improved lateral current spreading for the QLEDs, which significantly relieves the crowding of holes and thus enhances hole transport capability across the CBP in QLEDs. Comprehensive analysis on the photoelectric properties of devices shows that the optimal thickness for MoO3 interlayer inserted in CBP is only ≈1 nm. The resulting devices with periodic two insertion layers of MoO3 into CBP exhibit better performance compared with the CBP-only ones, such that the peak current efficiency is 88.7 cd A-1 corresponding to the external quantum efficiency of 20.6%. Furthermore, the resulting QLEDs show an operational lifetime almost 2.5 times longer compared to CBP-only devices.
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Affiliation(s)
- Qianqian Wu
- Key Laboratory of Advanced Display and System Applications of Ministry of EducationShanghai University149 Yanchang RoadShanghai200072China
| | - Fan Cao
- Key Laboratory of Advanced Display and System Applications of Ministry of EducationShanghai University149 Yanchang RoadShanghai200072China
| | - Haoran Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of EducationShanghai University149 Yanchang RoadShanghai200072China
| | - Jianquan Kou
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of Technology5340 Xiping Road, Beichen DistrictTianjin300401China
| | - Zi‐Hui Zhang
- State Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of Technology5340 Xiping Road, Beichen DistrictTianjin300401China
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of EducationShanghai University149 Yanchang RoadShanghai200072China
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2
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Kalina T. Reproducibility of Flow Cytometry Through Standardization: Opportunities and Challenges. Cytometry A 2019; 97:137-147. [DOI: 10.1002/cyto.a.23901] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 09/04/2019] [Accepted: 09/11/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Tomas Kalina
- CLIP‐Childhood Leukemia Investigation Prague, Department of Pediatric Hematology and Oncology2nd Medical School, Charles University and University Hospital Motol Prague Czech Republic
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3
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Chattopadhyay PK, Winters AF, Lomas WE, Laino AS, Woods DM. High-Parameter Single-Cell Analysis. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:411-430. [PMID: 30699035 DOI: 10.1146/annurev-anchem-061417-125927] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thousands of transcripts and proteins confer function and discriminate cell types in the body. Using high-parameter technologies, we can now measure many of these markers at once, and multiple platforms are now capable of analysis on a cell-by-cell basis. Three high-parameter single-cell technologies have particular potential for discovering new biomarkers, revealing disease mechanisms, and increasing our fundamental understanding of cell biology. We review these three platforms (high-parameter flow cytometry, mass cytometry, and a new class of technologies called integrated molecular cytometry platforms) in this article. We describe the underlying hardware and instrumentation, the reagents involved, and the limitations and advantages of each platform. We also highlight the emerging field of high-parameter single-cell data analysis, providing an accessible overview of the data analysis process and choice of tools.
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Affiliation(s)
- Pratip K Chattopadhyay
- Precision Immunology Laboratory, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA;
| | - Aidan F Winters
- Precision Immunology Laboratory, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA;
| | - Woodrow E Lomas
- Precision Immunology Laboratory, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA;
| | - Andressa S Laino
- Precision Immunology Laboratory, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA;
| | - David M Woods
- Precision Immunology Laboratory, Perlmutter Cancer Center, NYU Langone Health, New York, NY 10016, USA;
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4
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Cantero J, Genescà M. Maximizing the immunological output of the cervicovaginal explant model. J Immunol Methods 2018; 460:26-35. [PMID: 29894750 DOI: 10.1016/j.jim.2018.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/16/2018] [Accepted: 06/06/2018] [Indexed: 12/24/2022]
Abstract
In the field of sexually transmitted infections (STI), the cervicovaginal explant (CVEx) model, not only provides the opportunity to study the different immunological arms present in these tissues under steady state conditions, but also their response against ex vivo infection with relevant pathogens. The methodology associated to the establishment of the HIV infection model in the cervicovaginal tissue was described in detail by Grivel et al. earlier (Grivel and Margolis, 2009). With this model as a foundation, we illustrate different approaches to obtain a large number of immunological readouts from a single piece of tissue, thus maximizing the immunological output obtained. Additionally, we discuss several ideas to study some of the immunological subsets present in this mucosal tissue by enriching them with the addition of distinct chemokines or specifically inducing their activation. Importantly, most of the methodology and concepts proposed here can be applied to study the immune subsets resident in other tissues. In the field of mucosal immunology, the possibility of studying resident immune subsets from tissue explants offers a great opportunity to understand the real players against invading pathogens and localized pathologies. Furthermore, this model allows for addressing the therapeutic benefit of modulating the activity of certain molecules and immune subsets against invading pathogens, which may infer their contribution to pathogen control and direct novel therapeutic interventions.
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Affiliation(s)
- Jon Cantero
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), 119-129 Passeig Vall d'Hebrón, 08035 Barcelona, Spain; Mucosal Immunology Unit, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Can Ruti Campus, Carretera de Can Ruti, camí de les escoles s/n, 08916 Badalona, Spain
| | - Meritxell Genescà
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebrón, Institut de Recerca (VHIR), 119-129 Passeig Vall d'Hebrón, 08035 Barcelona, Spain; Mucosal Immunology Unit, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Can Ruti Campus, Carretera de Can Ruti, camí de les escoles s/n, 08916 Badalona, Spain.
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5
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Kovacic S, Samii L, Curmi PMG, Linke H, Zuckermann MJ, Forde NR. Design and Construction of the Lawnmower, An Artificial Burnt-Bridges Motor. IEEE Trans Nanobioscience 2015; 14:305-12. [DOI: 10.1109/tnb.2015.2393872] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Sun Y, Shen C, Wang J, Lu Y. Facile synthesis of biocompatible N, S-doped carbon dots for cell imaging and ion detecting. RSC Adv 2015. [DOI: 10.1039/c4ra13820a] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A facile, simple, effective and green method has been developed to synthesize nitrogen and sulfur co-doped carbon dots (N, S-CDs) from heparin sodium.
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Affiliation(s)
- Yupeng Sun
- Department of Polymer Science and Engineering
- State Key Laboratory of Coordination Chemistry
- Key Laboratory of High Performance Polymer Materials and Technology of Ministry of Education
- School of Chemistry and Chemical Engineering
- Nanjing University
| | - Chen Shen
- Department of Polymer Science and Engineering
- State Key Laboratory of Coordination Chemistry
- Key Laboratory of High Performance Polymer Materials and Technology of Ministry of Education
- School of Chemistry and Chemical Engineering
- Nanjing University
| | - Jing Wang
- Department of Polymer Science and Engineering
- State Key Laboratory of Coordination Chemistry
- Key Laboratory of High Performance Polymer Materials and Technology of Ministry of Education
- School of Chemistry and Chemical Engineering
- Nanjing University
| | - Yun Lu
- Department of Polymer Science and Engineering
- State Key Laboratory of Coordination Chemistry
- Key Laboratory of High Performance Polymer Materials and Technology of Ministry of Education
- School of Chemistry and Chemical Engineering
- Nanjing University
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7
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Melenhorst JJ, Castillo P, Hanley PJ, Keller MD, Krance RA, Margolin J, Leen AM, Heslop HE, Barrett AJ, Rooney CM, Bollard CM. Graft versus leukemia response without graft-versus-host disease elicited by adoptively transferred multivirus-specific T-cells. Mol Ther 2014; 23:179-83. [PMID: 25266309 DOI: 10.1038/mt.2014.192] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 09/22/2014] [Indexed: 11/09/2022] Open
Abstract
A 12-year-old boy with refractory acute lymphoblastic leukemia received a haploidentical transplant from his mother. As prophylaxis for Epstein-Barr virus (EBV), cytomegalovirus (CMV) and adenovirus, he received ex vivo expanded virus-specific donor T cells 3.5 months after transplant. Four weeks later leukemic blasts bearing the E2A deletion, identified by fluorescent in situ hybridization (FISH), appeared transiently in the blood followed by a FISH-negative hematological remission, which was sustained until a testicular relapse 3.5 months later. Clearance of the circulating leukemic cells coincided with a marked increase in circulating virus-specific T cells. The virus-specific cytotoxic T-cell (CTL) line showed strong polyfunctional reactivity with the patient's leukemic cells but not phytohemagglutinin (PHA) blasts, suggesting that virus-specific CTL lines may have clinically significant antileukemia activity.
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Affiliation(s)
- Jan J Melenhorst
- 1] Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA [2] Translational Research Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul Castillo
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Patrick J Hanley
- Program for Cell Enhancement and Technologies for Immunotherapy, Sheikh Zayed Institute for Pediatric Surgical Innovation, and Center for Cancer and Immunology Research, Children's National Health System, Washington, District of Columbia, USA
| | - Michael D Keller
- Program for Cell Enhancement and Technologies for Immunotherapy, Sheikh Zayed Institute for Pediatric Surgical Innovation, and Center for Cancer and Immunology Research, Children's National Health System, Washington, District of Columbia, USA
| | - Robert A Krance
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Judith Margolin
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Ann M Leen
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Helen E Heslop
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - A John Barrett
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Cliona M Rooney
- Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA
| | - Catherine M Bollard
- 1] Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children's Hospital and Houston Methodist Hospital, Houston, Texas, USA [2] Program for Cell Enhancement and Technologies for Immunotherapy, Sheikh Zayed Institute for Pediatric Surgical Innovation, and Center for Cancer and Immunology Research, Children's National Health System, Washington, District of Columbia, USA
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Bruno JG, Richarte AM, Phillips T, Savage AA, Sivils JC, Greis A, Mayo MW. Development of a fluorescent enzyme-linked DNA aptamer-magnetic bead sandwich assay and portable fluorometer for sensitive and rapid leishmania detection in sandflies. J Fluoresc 2013; 24:267-77. [PMID: 24222436 DOI: 10.1007/s10895-013-1315-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 10/09/2013] [Indexed: 01/14/2023]
Abstract
A fluorescent peroxidase-linked DNA aptamer-magnetic bead sandwich assay is described which detects as little as 100 ng of soluble protein extracted from Leishmania major promastigotes with a high molarity chaotropic salt. Lessons learned during development of the assay are described and elucidate the pros and cons of using fluorescent dyes or nanoparticles and quantum dots versus a more consistent peroxidase-linked Amplex Ultra Red (AUR; similar to resazurin) fluorescence version of the assay. While all versions of the assays were highly sensitive, the AUR-based version exhibited lower variability between tests. We hypothesize that the AUR version of this assay is more consistent, especially at low analyte levels, because the fluorescent product of AUR is liberated into bulk solution and readily detectable while fluorophores attached to the reporter aptamer might occasionally be hidden behind magnetic beads near the detection limit. Conversely, fluorophores could be quenched by nearby beads or other proximal fluorophores on the high end of analyte concentration, if packed into a small area after magnetic collection when an enzyme-linked system is not used. A highly portable and rechargeable battery-operated fluorometer with on board computer and color touchscreen is also described which can be used for rapid (<1 h) and sensitive detection of Leishmania promastigote protein extracts (∼ 100 ng per sample) in buffer or sandfly homogenates for mapping of L. major parasite geographic distributions in wild sandfly populations.
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Affiliation(s)
- John G Bruno
- Operational Technologies Corporation, 4100 NW Loop 410, Suite 230, San Antonio, TX, 78229, USA,
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9
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Zhang W, Hubbard A, Brunhoeber P, Wang Y, Tang L. Automated Multiplexing Quantum Dots in Situ Hybridization Assay for Simultaneous Detection of ERG and PTEN Gene Status in Prostate Cancer. J Mol Diagn 2013; 15:754-64. [DOI: 10.1016/j.jmoldx.2013.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/22/2013] [Accepted: 06/05/2013] [Indexed: 11/17/2022] Open
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10
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Duong H, Han M. A multispectral LED array for the reduction of background autofluorescence in brain tissue. J Neurosci Methods 2013; 220:46-54. [PMID: 23994358 PMCID: PMC3856220 DOI: 10.1016/j.jneumeth.2013.08.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 07/18/2013] [Accepted: 08/20/2013] [Indexed: 11/30/2022]
Abstract
The presence of fixative-induced and cellular-derived artifactual autofluorescences (AAFs) presents a challenge in histological analysis involving immunofluorescence. We have established a simple and highly effective method for the reduction of AAFs that are ubiquitous in fixed mammalian brain and other tissues. A compact AAF-quenching photo-irradiation device was constructed using a commercially available light emitting diode (LED) array, cooling unit, and supporting components. The LED panel is comprised of an array of multispectral high intensity LEDs which serve as the illumination source for the photo-irradiation process. Rabbit and cat brain specimens of 5 μm- and 40 μm-thicknesses, respectively, were photo-irradiated for various durations. The AAFs were reduced to near tissue background levels after 24h of treatment for both deparaffinized and paraffinized rabbit brain specimens, and for the free-floating cat brain specimens. Subsequent immunofluorescence staining using primary antibodies against GFAP, NeuN, Iba-1, and MAP-2, and the corresponding Qdot(®) and Alexafluor(®) fluoroconjugates confirmed that the LED photo-irradiation treatment did not compromise the efficiency of the immunofluorescence labeling. The use of the device is not labor intensive, and only requires minimal tissue processing and experimental set-up time, with very low maintenance and operating costs. Finally, multiple specimens, in both slide and well-plate format, can be simultaneously photo-irradiated, thus, allowing for scalable batch processing.
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Affiliation(s)
- Haison Duong
- Huntington Medical Research Institutes (HMRI), 734 Fairmount Avenue, Pasadena, CA 91105, United States.
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11
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Cappella P, Giansanti V, Pulici M, Gasparri F. From "Click" to "Fenton" chemistry for 5-bromo-2'-deoxyuridine determination. Cytometry A 2013; 83:989-1000. [PMID: 23943293 DOI: 10.1002/cyto.a.22343] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 07/08/2013] [Accepted: 07/14/2013] [Indexed: 12/24/2022]
Abstract
Ascorbic acid (AA) and copper have been increasingly employed in flow cytometry (FCM) and high content analysis (HCA) since the introduction of "click chemistry" as a non-destructive alternative to classical 5-bromo-2'-deoxyuridine (BrdU) immunodetection for DNA synthesis and proliferation assays. Mixtures of ascorbate and catalytic copper, under certain experimental conditions, act as oxidizing agent, catalyzing the formation of reactive hydroxyl radicals through hydrogen peroxides decomposition via Fenton reaction. We developed a procedure for BrdU incorporation detection based on the use of AA and cupric ions as DNA damaging agents. Optimal DNA damaging conditions were identified and found to provide results comparable with "click" 5-ethynyl-deoxyuridine (EdU) cycloaddition approach and classical BrdU immunodetection. Scavenger agents were found to prevent hydroxyl-induced DNA damages, providing the proof-of-concept for the use of this procedure for DNA denaturation prior to BrdU detection. We demonstrated hydroxyl radicals' reaction to be readily applicable to HCA and FCM assays, for both classical BrdU immunostaining and EdU cycloaddition procedure. This technique was successfully employed for BrdU pulse-chase experiments and in multiparametric immunofluorescence assays for the simultaneous detection of labile phosphoproteins in intact cells. The use of AA/Cu prior to immunodetection for BrdU incorporation assays is a viable alternative to chemical/physical DNA denaturing agents (acids or heat), since it allows preservation of labile epitopes such as phosphoproteins, and over enzymatic agents (digestion with DNases) for its lower cost.
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Affiliation(s)
- Paolo Cappella
- Department of Biology Nerviano Medical Sciences, Via Pasteur 10, 20014, Nerviano, Italy
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12
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Chattopadhyay PK, Gaylord B, Palmer A, Jiang N, Raven MA, Lewis G, Reuter MA, Nur-ur Rahman AKM, Price DA, Betts MR, Roederer M. Brilliant violet fluorophores: a new class of ultrabright fluorescent compounds for immunofluorescence experiments. Cytometry A 2012; 81:456-66. [PMID: 22489009 DOI: 10.1002/cyto.a.22043] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 02/12/2012] [Accepted: 02/28/2012] [Indexed: 01/11/2023]
Abstract
The Nobel Prize in Chemistry was awarded in 2000 for the discovery of conductive organic polymers, which have subsequently been adapted for applications in ultrasensitive biological detection. Here, we report the first use of this new class of fluorescent probes in a diverse range of cytometric and imaging applications. We demonstrate that these "Brilliant Violet" reporters are dramatically brighter than other UV-violet excitable dyes, and are of similar utility to phycoerythrin (PE) and allophycocyanin (APC). They are thus ideally suited for cytometric assays requiring high sensitivity, such as MHC-multimer staining or detection of intracellular antigens. Furthermore, these reporters are sensitive and spectrally distinct options for fluorescence imaging, two-photon microscopy and imaging cytometry. These ultra-bright materials provide the first new high-sensitivity fluorescence probes in over 25 years and will have a dramatic impact on the design and implementation of multicolor panels for high-sensitivity immunofluorescence assays.
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Affiliation(s)
- Pratip K Chattopadhyay
- ImmunoTechnology Section, Vaccine Research Center, NIAID, NIH, Bethesda, Maryland 20892, USA.
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Chattopadhyay PK, Roederer M. Cytometry: today's technology and tomorrow's horizons. Methods 2012; 57:251-8. [PMID: 22391486 DOI: 10.1016/j.ymeth.2012.02.009] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 02/13/2012] [Accepted: 02/20/2012] [Indexed: 11/19/2022] Open
Abstract
Flow cytometry has been the premier tool for single cell analysis since its invention in the 1960s. It has maintained this position through steady advances in technology and applications, becoming the main force behind interrogating the complexities of the immune system. Technology development was a three-pronged effort, including the hardware, reagents, and analysis algorithms to allow measurement of as many as 20 independent parameters on each cell, at tens of thousands of cells per second. In the coming years, cytometry technology will integrate with other techniques, such as transcriptomics, metabolomics, and so forth. Ongoing efforts are aimed at algorithms to analyse these aggregated datasaets over large numbers of samples. Here we review the development efforts heralding the next stage of flow cytometry.
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Affiliation(s)
- Pratip K Chattopadhyay
- ImmunoTechnology Section, VRC, NIAID, NIH, 40 Convent Dr., Room 5509, Bethesda, MD 20817, USA
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Optimization of a whole blood intracellular cytokine assay for measuring innate cell responses to mycobacteria. J Immunol Methods 2011; 376:79-88. [PMID: 22155193 DOI: 10.1016/j.jim.2011.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 10/10/2011] [Accepted: 11/23/2011] [Indexed: 02/02/2023]
Abstract
Innate cells are essential for host defense against invading pathogens, and the induction and direction of adaptive immune responses to infection. We developed and optimized a flow cytometric assay that allows measurement of intracellular cytokine expression by monocytes, dendritic cells (DC) and granulocytes, as well as cellular uptake of green-fluorescent protein (GFP)-expressing mycobacteria, in very small volumes of peripheral blood. We show that innate cell stimulation resulted in increased granularity of monocytes and mDC and decreased granulocyte granularity that precluded flow cytometric discernment of granulocytes from monocytes and myeloid DC by forward and side scatter gating. Anti-CD66a/c/e antibody staining allowed reliable identification and exclusion of granulocytes for subsequent delineation of monocytes and myeloid DC. Intracellular cytokine expression by granulocytes, monocytes and mDC was remarkably sensitive to the dose of mycobacterial inoculum. Moreover, activation of monocytes and mDC with live BCG reduced expression levels of CD14 and CD11c, respectively, necessitating optimization of staining conditions to reliably measure these lineage markers. Finally, we characterized expression of IL-12/23p40, TNF-α, IL-6, and IL-10, by GFP(+) and GFP(-) monocytes and mDC from 25 healthy adults. This assay may be applied to the study of innate cell responses to any GFP-expressing pathogen, and can be performed on blood volumes as low as 200 μL per condition, making the assay particularly suitable for pediatric studies.
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Abstract
The development of quantum dot (QD) technology represents one of the most dramatic advances in flow cytometry history, offering the opportunity for highly multiplexed experiments and allowing better resolution of dimly staining markers. Here, we guide users through the technical aspects of using QDs (including instrumentation and antibody conjugation), demonstrate why QDs are useful in multicolor flow cytometry, and describe some of the challenges investigators may face when adopting this technology.
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