KCS

Mass spectrometry (MS)-based quantitative proteomic methods have been widely used for protein biomarker validation. Recent advances in mass spectrometers and liquid chromatography allowed various ways of parallel reaction monitoring (PRM) technique to be developed for more accurate quantitative information or to enlarge target lists. However, in case of accuracy, conventional PRM technique produces quantitative information of labeled peptide and endogenous peptide separately from each tandem scans. The targeting peptides, both labeled peptide and endogenous peptide, are listed in MS method altogether, so each peptides are scanned separately. Calculating profile area from two different scans to obtain ratio between labeled peptide and corresponding endogenous peptide can provide inaccurate quantitative information. In order to avoid such discrepancy between scans, we employed novel quantification method using wide isolation window to capture both labeled peptide and endogenous peptide in single tandem scan. By using wide-band PRM method coupled with high resolution dual online-ultrahigh pressure liquid chromatography (DO-UHPLC) system, we were able to quantify 150 targeted peptides from pancreatic ductal adenocarcinoma(PDAC) sample in single experiment.