SILAC labelling is a versatile tool that relies on the in vivo metabolic labelling of proteins with non-radioactive, isotopically-labelled amino acids. Two to three different cell culture samples can be combined and simultaneously analysed by LC-MSMS.
SILAC or Stable Isotopic Labelling of Amino acids in Cell culture. Cells are grown in media containing heavier, isotopically-labelled versions of arginine (R) and lysine (K). As the cells divide, the labelled amino acids are metabolically incorporated into new proteins.
SILAC experiments can be performed using double (light vs. heavy) or triple (light vs. medium vs. heavy) media.
As trypsin cleaves proteins after R and K, only these amino acids are usually labelled. This ensures that all peptides in the sample (excluding the C-terminal peptide when terminating in another amino acid) are labelled.
Typical labels are: