Atlas Antibodies Presents QPrEST Standards for Absolute Quantification of Proteins using Mass Spectrometry

QPrESTs consists of 50-150 amino acids identical to a part of the corresponding human protein. They are produced recombinantly in the presence of stable isotope-labeled (i.e. heavy) amino acids to generate protein standards. Targeted proteomics is a method allowing absolute quantification of the proteins of interest by comparing the MS signal intensities of the stable isotope standard with an endogenous peptide that is generated upon proteolytic digestion of the target protein.

One of the advantages of QPrESTs over other available protein standards is that they are added to the sample early in the workflow, prior to proteolytic digestion. The shared amino acid sequence of the QPrEST and the endogenous protein enables the QPrEST to correct for variation introduced during sample digestion, thereby increasing accuracy in quantification.

John Daicic, CEO of Atlas Antibodies, commented: “Just like our antibodies, the new, pre-quantified QPrEST standards are available for the vast majority of...