Mass spectrometric analysis of proteins using stable isotopes of pyrylium derivates as labels

摘要

The present invention provides a protein analysis method using a combination of two or more kinds of stable isotopes of a compound represented by the formula (I):; wherein R₁, R₂ and R₃ are the same or different and each is hydrogen, halogen or alkyl, or a salt thereof, as a labeling compound to produce a difference in the mass of the same kind of protein contained in each sample.