SRM Assay for PD-L1

摘要

The current disclosure provides for specific peptides, and derived ionization characteristics of the peptides, from the PD-L1 protein that are particularly advantageous for quantifying the PD-L1 protein directly in biological samples that have been fixed in formalin by the method of Selected Reaction Monitoring (SRM) mass spectrometry, or what can also be termed as Multiple Reaction Monitoring (MRM) mass spectrometry. Such biological samples are chemically preserved and fixed wherein said biological sample is selected from tissues and cells treated with formaldehyde containing agents/fixatives including formalin-fixed tissue/cells, formalin-fixed/paraffin embedded (FFPE) tissue/cells, FFPE tissue blocks and cells from those blocks, and tissue culture cells that have been formalin fixed and/or paraffin embedded. PD-L1 peptides having modified or unmodified residues can be quantitated. An example of a modification of a PD-L1 fragment peptide is a phosphorylated tyrosine, threonine, serine, and/or other amino acid residues within the peptide sequence.

主权项

1. A method for measuring the level of the PD-L1 protein in a biological sample, comprising detecting and/or quantifying the amount of one or more modified and/or unmodified PD-L1 protein fragment peptides in a protein digest prepared from said biological sample using mass spectrometry; and calculating the level of modified or unmodified PD-L1 protein in said sample; and
wherein said amount is a relative amount or an absolute amount.