A colorimetric method for monitoring tryptic digestion prior to shotgun proteomics.

Tryptic digestion is an important preanalytical step in shotgun proteomics because inadequate or excessive digestion can result in a failed or incomplete experiment. Unfortunately, this step is not routinely monitored before mass spectrometry because methods available for protein digestion monitoring either are time/sample consuming or require expensive equipment. To determine if a colorimetric method (ProDM Kit) can be used to identify the extent of tryptic digestion that yields the best proteomics outcome, plasma and serum digested for 8 h and 24 h were screened with ProDM, Bioanalyzer, and LC/MS/MS, and the effect of digestion on the number of proteins identified and sequence coverage was compared.