Acrylamide--a cysteine alkylating reagent for quantitative proteomics.

Mass spectrometry-based relative quantification of proteins is often achieved by the labeling of two samples with isotopically light and heavy reagents. The intensities of the ions with different masses, but same chemical properties, can be reliably used for determining relative quantities. Several strategies of labeling with various weakness and strength and degrees of complexity have been described. In this chapter, we describe a simple and inexpensive protein-labeling procedure based on the use of acrylamide and deuterated acrylamide as a cysteine alkylating reagent. Gel electrophoresis is one of the most commonly used techniques for analyzing/visualizing proteins, thus, we emphasize the use of acrylamide as a labeling procedure for quantifying proteins isolated by one- and two-dimensional polyacrylamide gel electrophoresis.