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Skaggs C, Kirkpatrick L, Wichert WRA, Skaggs N, Manicke NE. A statistical approach to optimizing paper spray mass spectrometry parameters. Rapid Commun Mass Spectrom 2020; 34:e8601. [PMID: 32043669 DOI: 10.1002/rcm.8601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Paper spray mass spectrometry (PS-MS) was used to analyze and quantify ampicillin, a hydrophilic compound and frequently utilized antibiotic. Hydrophilic molecules are difficult to analyze via PS-MS due to their strong binding affinity to paper substrates and low ionization efficiency, among other reasons. METHODS Solvent and paper parameters were optimized to increase the extraction of ampicillin from the paper substrate. After optimizing these key parameters, a Resolution IV 1/16 fractional factorial design with two center points was employed to screen eight different design parameters simultaneously. RESULTS Pore size, sample volume, and solvent volume were the most significant factors affecting average peak area under the curve (AUC) and the signal-to-blank (S/B) ratio for the 1 μg/mL ampicillin calibrant. After optimizing the key parameters, a linear calibration curve with a range of 0.2 μg/mL to 100 μg/mL was generated (R2 = 0.98) and the limit of detection (LOD) and lower limit of quantification (LLOQ) were calculated to be 0.07 μg/mL and 0.25 μg/mL, respectively. CONCLUSIONS The statistical optimization procedure undertaken here increased the mass spectral signal intensity by more than a factor of 40. This statistical method of screening followed by optimization experiments proved faster and more efficient, and produced more drastic improvements than typical one-factor-at-a-time experiments.
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Affiliation(s)
- Christine Skaggs
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Lindsey Kirkpatrick
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - William R A Wichert
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Nicole Skaggs
- Technical Problem Solver, General Motors Proving Grounds, Milford, MI, 48380, USA
| | - Nicholas E Manicke
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
- Forensics and Investigative Sciences, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202, USA
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Kumar S, AlAbed D, Worden A, Novak S, Wu H, Ausmus C, Beck M, Robinson H, Minnicks T, Hemingway D, Lee R, Skaggs N, Wang L, Marri P, Gupta M. A modular gene targeting system for sequential transgene stacking in plants. J Biotechnol 2015; 207:12-20. [PMID: 25913173 DOI: 10.1016/j.jbiotec.2015.04.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 03/14/2015] [Accepted: 04/03/2015] [Indexed: 11/16/2022]
Abstract
A modular, selection-based method was developed for site-specific integration of transgenes into a genomic locus to create multigene stacks. High-frequency gene targeting was obtained using zinc finger nuclease (ZFN)-mediated double-strand break (DSB) formation at a pre-defined target genomic location using a unique intron directly downstream of a promoter driving a selectable marker gene to facilitate homology between target and donor sequences. In this system, only insertion into the target locus leads to a functional selectable marker, and regeneration from random insertions of the promoterless donor construct are reduced on selection media. A new stack of transgenes can potentially be loaded with each successive cycle of gene targeting by exchanging the selectable marker gene using the intron homology. This system was tested in maize using the pat selectable marker gene, whereby up to 30% of the plants regenerated on Bialaphos-containing medium were observed to have the donor construct integrated into the target locus. Unlike previous gene targeting methods that utilize defective or partial genes for selecting targeted events, the present method exchanges fully functional genes with every cycle of targeting, thereby allowing the recycling of selectable marker genes, hypothetically for multiple generations of gene targeting.
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Affiliation(s)
- Sandeep Kumar
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA.
| | - Diaa AlAbed
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Andrew Worden
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Stephen Novak
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Huixia Wu
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Carla Ausmus
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Margaret Beck
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Heather Robinson
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Tatyana Minnicks
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Daren Hemingway
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Ryan Lee
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Nicole Skaggs
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Lizhen Wang
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Pradeep Marri
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Manju Gupta
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
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