2022 Volume 7 Issue 1 Pages 15-26
Proteomics has advanced over the past 25 years with a primary focus on mass spectrometry. Shotgun LC/MS, in particular, has enabled the identification of a vast number of proteins, regardless of species, as long as a database of amino acid sequences and other information is available. However, LC/MS quantification has not been very well managed in terms of validation, and several issues remain, especially in the field of plasma proteomics. This is where the Proximity Extension Assay (PEA) was introduced. This is a method combining antibody and oligonucleotide amplification, which is called immuno-PCR. PEA method facilitates the analysis of cytokines and other substances in blood that are difficult to detect by LC/MS while ensuring specificity, and is designed to guarantee reliability in quantitation. It has been applied to the measurement of plasma and serum samples from more than 1,000 subjects, and more than 3,000 types of proteins have recently been quantified. In the future, LC/MS may be used for the search and identification of plasma proteins, while PEA may be used for quantitative analysis.
