We describe a method to accurately quantify human tumor proteomes by combining a 
mixture of five stable-isotope labeling by amino acids in cell culture 
(SILAC)-labeled cell lines with human carcinoma tissue. This generated hundreds 
of thousands of isotopically labeled peptides in appropriate amounts to serve as 
internal standards for mass spectrometry-based analysis. By decoupling the 
labeling from the measurement, this super-SILAC method broadens the scope of 
SILAC-based proteomics.