| abstract |
The present invention provides a method for directly quantifying a cyclin-dependent kinase inhibitor 2A (p16) protein in a biological sample immobilized to formalin by SRM / MRM mass spectrometry. Protein samples are prepared from biological samples using, for example, liquid tissue reagents and protocols, and the p16 protein is quantitated in samples generated by quantifying at least one fragment peptide from p16 in a protein sample. The peptide can be quantified in a modified or unmodified form. An example of a modified form of the p16 peptide is phosphorylation of tyrosine, threonine, serine and / or other amino acid residues in the peptide sequence. |