Specificity of Detection Is the Key Attribute of Selected Reaction Monitoring

Abstract

Selected reaction monitoring uses tandem mass spectrometry to create instrumental conditions where only specific peptides can be detected. The two stages of the mass spectrometer are synchronized so that a signal is seen only when a molecular ion with a specific m/z is formed and that molecular ion fragments to a product ion with a specific m/z. The specificity of the analysis is increased by the unique amino acid sequence that defines a protein’s identity and the effects of that unique amino acid sequence on the other parts of the overall assay, including the protein digestion and liquid chromatography. The result is the ability to selectively measure, with confidence and accuracy, any protein in a complex mixture.