Relative quantitation of intact proteins of bacterial cell extracts using coextracted proteins as internal standards.

摘要: A method for quantitating protein expression using LC/MS of whole proteins is described. This based on the fact that some present in cells are abundant universal whose levels exhibit little variation. demonstrates these coextracted can be used as internal standards to which other sample compared. By comparing intensities a selected marker proteins, or standards, relative ratio obtained. then determine amount between cellular extracts. The validity this approach described standard mixture, well as, E. coli were known differentially express green fluorescent protein.