Shu Q, Liu S, Alonzi T, LaCourse SM, Singh DK, Bao D, Wamalwa D, Jiang L, Lyon CJ, John-Stewart G, Kaushal D, Goletti D, Hu T. Assay design for unambiguous identification and quantification of circulating pathogen-derived peptide biomarkers. Theranostics. 2022 Mar 21;12(6):2948-2962. doi: 10.7150/thno.70373. PMID: 35401822; PMCID: PMC8965485.
Liquid chromatography coupled mass spectrometry (LC-MS) operating in targeted mass spectrometry (MS) including multiple reaction monitoring (MRM) mode is an accurate analytical method. Integrating with nanoelectrospray-tandem MS (NanoES-MS/MS) and immunoprecipitation (IP), it becomes a promising method in detecting pathogen derived antigens which are at extremely low concentrations, such as mycobacterium tuberculosis (Mtb) secreted 10 kDa culture filtrate antigen (CFP-10). We employed an optimum denaturing condition for trypsin digestion and imunoprecipitation of targeted peptides and applied this method in clinical samples.