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Qualitative and Quantitative Determination of Bioactive Phytochemicals in Selected Cassia Species Using HPLC-ESI-QTOF-MS and UPLC-ESI-QqQLIT-MS/MS
Published in Brijesh Kumar, Vikas Bajpai, Vikaskumar Gond, Subhashis Pal, Naibedya Chattopadhyay, Phytochemistry of Plants of Genus Cassia, 2021
Brijesh Kumar, Vikas Bajpai, Vikaskumar Gond, Subhashis Pal, Naibedya Chattopadhyay
All the MS parameters for 18 compounds i.e., precursor ion, product ion, declustering potential (DP), entrance potential (EP), collision energy (CE) and cell exit potential (CXP) were optimized in negative ESI mode, by flow injection analysis (FIA). The chemical structures of 18 components were characterized based on their retention behaviour and MS information such as quasimolecular ions [M-H]-, fragment ions [M-H-COO]-, [M-H-COO-CH3]-, [M- CO-H2O] compared to related standards and literatures (Yu et al., 2009; Xia et al., 2011; Wei et al., 2013; Pandey et al., 2014). MRM parameters were optimized to achieve the most abundant, specific and stable MRM transition for each compound as shown in Table 2.1. MRM extracted ion chromatogram of 18 analytes are shown in Figure 2.1.
Rapid Isolation of Lysosomes from Cultured Cells Using a Twin Strep Tag
Published in Bruno Gasnier, Michael X. Zhu, Ion and Molecule Transport in Lysosomes, 2020
Jian Xiong, Jingquan He, Michael X. Zhu, Guangwei Du
LC-MS analysis is performed in MRM mode. Data analysis is carried out by using Agilent Mass Hunter workstation software. All the identified amino acids may be normalized against the spiked isotopic labelled standard.
Emerging Biomedical Analysis
Published in Lawrence S. Chan, William C. Tang, Engineering-Medicine, 2019
QqQMS is a tandem mass spectrometer that has two quadrupoles serving as mass filters with an RF-only quadrupole between them to act as a collision cell for CID. Selected reaction monitoring (SRM), also known as multiple reaction monitoring (MRM), can be performed in this type of instrument. In SRM mode, the first quadrupole (Q1) scans for predefined specific precursor ions which are subjected to CID with helium or argon in the second quadrupole (Q2) to produce fragments. Specific fragments of the precursor ion are filtered in the third quadrupole and detected by electron multipliers. This dual-step ion selection allows for highly specific detection with high sensitivity and low background interference. Thus, QqQMS is often the instrument of choice for quantitative analysis of both small and large molecules.
An overview of proteomic methods for the study of ‘cytokine storms’
Published in Expert Review of Proteomics, 2021
Paul David, Frederik J. Hansen, Adil Bhat, Georg F. Weber
In contrast to antibody-based assays, MS-based multiple reaction monitoring (MRM) assay allows for the simultaneous detection and quantification of several biomarkers in various biological samples with a single analysis run, without the need of specific antibodies. The detection of MRM-based assays for absolute quantification has been reported to have high specificity and sensitivity. Moreover, MRM-based assays are more time- and cost-efficient than ELISAs in terms of per sample and parameter, and additionally novel analytes can be easily analyzed. Technically MRM assays are based on proteolytically cleaved peptides that are unique to the target proteins [9]. The identification and quantifications depend on the selection of those specific peptides and their fragments and the exclusion of all other analytes in the sample. Thus, MRM facilitates the quantification of proteins in a complex sample matrix such as human serum or plasma. Over the last period, peptide-based MRM assays have been successfully applied for the detection and quantitation of biomarkers in various diseases like coronary artery diseases, different types of cancer, hypertension, arthritis, and viral diseases [10–14].
Applications of multiple reaction monitoring targeted proteomics assays in human plasma
Published in Expert Review of Molecular Diagnostics, 2019
Georgia Kontostathi, Manousos Makridakis, Jerome Zoidakis, Antonia Vlahou
The aim of this review is to offer an overview of MRM applications for protein quantification in human plasma, in the context of various non-communicable diseases. Towards that end, a PubMed search was performed using the following keywords: ‘MRM plasma proteomics’ OR ‘MRM plasma proteomic’ OR ‘MRM plasma proteome’ OR ‘SRM plasma proteomics’ OR ‘SRM plasma proteomic’ OR ‘SRM plasma proteome’ for the time period of 2013-February 2019 (Figure 1). This search resulted in 182 articles which were subjected to shortlisting, after excluding clearly methodological papers focusing on the establishment and application of MRM in normal human plasma, and studies using biological matrices other than plasma or involving measurement of metabolites. This resulted, collectively, in a final list of 43 studies (Supplementary Table S1) presenting plasma proteomic MRM data, which in a small number of cases, were also complemented with metabolomics or data from other biological matrices (as presented below). For comparison and to increase comprehensiveness, a respective search was also performed using the keyword 'serum’ instead of plasma and results are summarized in Supplementary Table S2.
Cancer biomarker discovery and translation: proteomics and beyond
Published in Expert Review of Proteomics, 2019
Ventzislava A. Hristova, Daniel W. Chan
Targeted proteomics is not limited to antibody methods. Selected Reaction Monitoring (SRM) and Multiple Reaction Monitoring (MRM) mass spectrometry techniques are emerging as reliable, high throughput assays for cancer biomarkers. Detection of target proteins is achieved with a triple quadrupole mass spectrometer, where specific peptides originating from the protein of interest are selected based on their mass to charge (m/z) ratio and subsequently fragmented into smaller components that are in turn quantified to assess protein abundance (Figure 2(c)) [24,25]. The principle of protein detection is identical for SRM and MRM, with the primary difference that MRM is the application of SRM to multiple peptide fragments. Identifying and quantifying multiple peptides from one or more target proteins simultaneously, makes MRM capable of multiplexing with high sensitivity and the technique of choice for most directed assays [26]. The primary advantage of MRM is the ability to detect multiple isoforms and post-translationally modified species for a given protein with high specificity in a single test run. In an effort to minimize invasive procedures, MRM assays are utilized for the detection of biomarker peptides in serum samples from breast and colorectal cancer patients among others [27,28].