scholarly journals Coupling Laser Diode Thermal Desorption with Acoustic Sample Deposition to Improve Throughput of Mass Spectrometry–Based Screening

2015 ◽  
Vol 21 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Zuzana Haarhoff ◽  
Andrew Wagner ◽  
Pierre Picard ◽  
Dieter M. Drexler ◽  
Tatyana Zvyaga ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Desorption ◽  
Laser Diode ◽  
High Throughput Screening ◽  
Solid Phase ◽  
Atmospheric Pressure Chemical Ionization ◽  
Label Free ◽  
Metabolite Formation ◽  
Cyp Inhibition ◽  
Sample Deposition

The move toward label-free screening in drug discovery has increased the demand for mass spectrometry (MS)–based analysis. Here we investigated the approach of coupling acoustic sample deposition (ASD) with laser diode thermal desorption (LDTD)–tandem mass spectrometry (MS/MS). We assessed its use in a cytochrome P450 (CYP) inhibition assay, where a decrease in metabolite formation signifies CYP inhibition. Metabolite levels for 3 CYP isoforms were measured as CYP3A4-1′-OH-midazolam, CYP2D6-dextrorphan, and CYP2C9-4′-OH-diclofenac. After incubation, samples (100 nL) were acoustically deposited onto a stainless steel 384-LazWell plate, then desorbed by an infrared laser directly from the plate surface into the gas phase, ionized by atmospheric pressure chemical ionization (APCI), and analyzed by MS/MS. Using this method, we achieved a sample analysis speed of 2.14 s/well, with bioanalytical performance comparable to the current online solid-phase extraction (SPE)–based MS method. An even faster readout speed was achieved when postreaction sample multiplexing was applied, where three reaction samples, one for each CYP, were transferred into the same well of the LazWell plate. In summary, LDTD coupled with acoustic sample deposition and multiplexing significantly decreased analysis time to 0.7 s/sample, making this MS-based approach feasible to support high-throughput screening (HTS) assays.

scholarly journals Development of a High-Throughput Affinity Mass Spectrometry (AMS) Platform Using Laser Diode Thermal Desorption Ionization Coupled to Mass Spectrometry (LDTD-MS)

2020 ◽  
pp. 247255522097959
Author(s):  
Aniruddha Sahasrabuddhe ◽  
Dylan Oakley ◽  
Kui Chen ◽  
John D. McCarter
Keyword(s):  
Mass Spectrometry ◽  
Small Molecule ◽  
Thermal Desorption ◽  
Laser Diode ◽  
High Throughput ◽  
Solid Phase ◽  
Atmospheric Pressure Chemical Ionization ◽  
Ionization Source ◽  
Robust Detection ◽  
Compound Libraries

Affinity selection mass spectrometry (MS) or, simply, affinity mass spectrometry (AMS) is a label-free technology that has been used to identify high-affinity ligands of target proteins of interest by screening against small-molecule compound libraries and identifying molecules that are enriched in the presence of the target protein. We have previously applied Agilent Technology’s (Santa Clara, CA) RapidFire solid-phase extraction (SPE)-based high-throughput MS technology to screen small-molecule libraries using AMS. However, SPE-based technologies rely on fluidics for desalting and separation prior to mass analysis with attendant high solvent consumption, relatively high sample volume requirements, risk of sample carryover, and frequent maintenance. To address these challenges, we have established an AMS platform using a laser diode thermal desorption–atmospheric pressure chemical ionization (LDTD-APCI) ionization source (Phytronix, Quebec, Canada) coupled with a SCIEX 5600+ TripleTOF MS (Framingham, MA). We also validated a data-independent acquisition (DIA) Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) method for the robust detection and analysis of small-molecule affinity hits. An informatics platform developed in-house has resulted in a streamlined data analysis workflow for high-throughput AMS screening campaigns and reduced data processing time without compromising data quality. Finally, 68,000 compounds were screened in a single plate and affinity selected hits were confirmed in an orthogonal enzyme activity assay.

scholarly journals The Evolution of MALDI-TOF Mass Spectrometry toward Ultra-High-Throughput Screening: 1536-Well Format and Beyond

2015 ◽  
Vol 21 (2) ◽  
pp. 176-186 ◽  
Author(s):  
Carl Haslam ◽  
John Hellicar ◽  
Adrian Dunn ◽  
Arne Fuetterer ◽  
Neil Hardy ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Throughput ◽  
High Throughput Screening ◽  
Solid Phase ◽  
Direct Detection ◽  
Sample Volume ◽  
Model Systems ◽  
Analysis Time ◽  
Label Free ◽  
Maldi Tof

Mass spectrometry (MS) offers a label-free, direct-detection method, in contrast to fluorescent or colorimetric methodologies. Over recent years, solid-phase extraction–based techniques, such as the Agilent RapidFire system, have emerged that are capable of analyzing samples in <10 s. While dramatically faster than liquid chromatography–coupled MS, an analysis time of 8–10 s is still considered relatively slow for full-diversity high-throughput screening (HTS). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) offers an alternative for high-throughput MS detection. However, sample preparation and deposition onto the MALDI target, as well as interference from matrix ions, have been considered limitations for the use of MALDI for screening assays. Here we describe the development and validation of assays for both small-molecule and peptide analytes using MALDI-TOF coupled with nanoliter liquid handling. Using the JMJD2c histone demethylase and acetylcholinesterase as model systems, we have generated robust data in a 1536 format and also increased sample deposition to 6144 samples per target. Using these methods, we demonstrate that this technology can deliver fast sample analysis time with low sample volume, and data comparable to that of current RapidFire assays.

scholarly journals MALDIViz: A Comprehensive Informatics Tool for MALDI-MS Data Visualization and Analysis

2017 ◽  
Vol 22 (10) ◽  
pp. 1246-1252 ◽  
Author(s):  
Kishore Kumar Jagadeesan ◽  
Simon Ekström
Keyword(s):  
Mass Spectrometry ◽  
High Throughput ◽  
High Throughput Screening ◽  
Web Application ◽  
Low Cost ◽  
Maldi Ms ◽  
Ionization Mass ◽  
Label Free ◽  
Label Free Detection ◽  
R Shiny

Recently, mass spectrometry (MS) has emerged as an important tool for high-throughput screening (HTS) providing a direct and label-free detection method, complementing traditional fluorescent and colorimetric methodologies. Among the various MS techniques used for HTS, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides many of the characteristics required for high-throughput analyses, such as low cost, speed, and automation. However, visualization and analysis of the large datasets generated by HTS MALDI-MS can pose significant challenges, especially for multiparametric experiments. The datasets can be generated fast, and the complexity of the experimental data (e.g., screening many different sorbent phases, the sorbent mass, and the load, wash, and elution conditions) makes manual data analysis difficult. To address these challenges, a comprehensive informatics tool called MALDIViz was developed. This tool is an R-Shiny-based web application, accessible independently of the operating system and without the need to install any program locally. It has been designed to facilitate easy analysis and visualization of MALDI-MS datasets, comparison of multiplex experiments, and export of the analysis results to high-quality images.

Rapid Determination of Chloramphenicol in Honey by Laser Diode Thermal Desorption Using Atmospheric Pressure Chemical Ionization-Tandem Mass Spectrometry

2013 ◽  
Vol 96 (3) ◽  
pp. 676-679 ◽  
Author(s):  
Grégory Blachon ◽  
Pierre Picard ◽  
Patrice Tremblay ◽  
Sarah Demers ◽  
Réal Paquin ◽  
...  
Keyword(s):  
Thermal Desorption ◽  
Laser Diode ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Atmospheric Pressure Chemical Ionization ◽  
Rapid Determination ◽  
Internal Standard ◽  
Honey Sample ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical

Abstract A high-throughput, rapid, and reliable method based on laser diode thermal desorption (LDTD) and atmospheric pressure chemical ionization coupled to tandem MS (APCI-MS/MS) was used to identify and quantify chloramphenicol (CAP) residues in honey. Sample pretreatment consisted of a liquid–liquid extraction of diluted honey in water with ethyl acetate containing stearic acid. After extraction, a 2 μL aliquot of the organic phase was deposited into a 96-well plate prior to detection by LDTD-APCI-MS/MS. The total analysis time was less than 6 s compared to several minutes for traditional chromatographic methods used for CAP detection, since no chromatographic separation was necessary. The extraction and analysis were made with honey samples of different color grading ranging from extra white to dark amber. The method showed good linearity (R2 = 0.99995) within a concentration range of 0.1 to 500 ng/g for CAP with D5-CAP as an internal standard. The RSD varied between 8 and 24% over the calibration range (n = 4). The method LOD for CAP in honey was 0.19 ng/g. This work demonstrates that LDTD-APCI-MS/MS could be used for fast and effective quantification of CAP in honey samples.

scholarly journals Pulsed Blue Laser Diode Thermal Desorption Microplasma Imaging Mass Spectrometry

2021 ◽  
Author(s):  
Alexander Knodel ◽  
Ulrich Marggraf ◽  
Edeltraut Hoffmann-Posorske ◽  
Sebastian Burhenn ◽  
Sebastian Brandt ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thermal Desorption ◽  
Laser Diode ◽  
Imaging Mass Spectrometry ◽  
Blue Laser ◽  
Blue Laser Diode

scholarly journals Confirmation of Eprinomectin, Moxidectin, Abamectin, Doramectin, and Ivermectin in Beef Liver by Liquid Chromatography/Positive Ion Atmospheric Pressure Chemical Ionization Mass Spectrometry

2000 ◽  
Vol 83 (1) ◽  
pp. 39-52 ◽  
Author(s):  
M Sher Ali ◽  
Tung Sun ◽  
Gina E McLeroy ◽  
Evan T Phillippo
Keyword(s):  
Mass Spectrometry ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Solid Phase ◽  
Atmospheric Pressure Chemical Ionization ◽  
Ionization Mass ◽  
Beef Liver ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Positive Ion

Abstract A liquid chromatographic (LC) multiresidue screening procedure was developed for determination of eprinomectin, moxidectin, abamectin, doramectin, and ivermectin in beef liver at 0, 25, 50, and 100 ppb levels. A procedure using low resolution LC/atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) was developed with further purification steps added to the quantitative LC method to confirm residues. Acetonitrile extracts of liver, prior to derivatization for LC analysis, were further purified by using a C8 solid-phase extraction cartridge and an alumina-B cartridge. The purified extract was analyzed by injection into an LC/positive ion APCI MS. Identity of the compound was confirmed by comparison of its retention time and relative intensity data with those of a standard or recovery from a fortified control liver sample. Anthelmintic drugs in acetonitrile extracts of liver containing eprinomectin, moxidectin, abamectin, doramectin, and ivermectin at 25 ppb, the lowest level of fortification used in the LC determinative method, were successfully confirmed.

scholarly journals Identification of an Arginase II Inhibitor via RapidFire Mass Spectrometry Combined with Hydrophilic Interaction Chromatography

2018 ◽  
Vol 24 (4) ◽  
pp. 457-465 ◽  
Author(s):  
Wataru Asano ◽  
Yu Takahashi ◽  
Motoaki Kawano ◽  
Yoshiji Hantani
Keyword(s):  
Mass Spectrometry ◽  
High Throughput ◽  
High Throughput Screening ◽  
Large Scale ◽  
Hydrophilic Interaction Chromatography ◽  
Label Free ◽  
Hydrophilic Interaction ◽  
High Concentration ◽  
Allosteric Site ◽  
Arginase Ii

Peripheral arterial disease (PAD) is an occlusive disease that can lead to atherosclerosis. The involvement of arginase II (Arg II) in PAD progression has been proposed. However, no promising drugs targeting Arg II have been developed to date for the treatment of PAD. In this study, we established a method for detecting the activity of Arg II via high-throughput label-free RapidFire mass spectrometry using hydrophilic interaction chromatography, which enables the direct measurement of l-ornithine produced by Arg II. This approach facilitated a robust high-concentration screening of fragment compounds and the identification of a fragment that inhibits the activity of Arg II. We further confirmed binding of the fragment to the potential allosteric site of Arg II using a surface plasmon resonance assay. We concluded that the identified fragment is a promising compound that may lead to novel drugs to treat PAD, and our method for detecting the activity of Arg II can be applied to large-scale high-throughput screening to identify other structural types of Arg II inhibitors.

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