Two kinds of protein isotopic labeling method are supported in our
biomarker discovery service: SILAC and LIT. The choice between LIT and SILAC labeling largely depends on the specific
requirements of a project. Both methods can be used to detect changes
in protein abundance as well as changes in posttranslational
modifications. SILAC is carried out by our customers during growth of
cells. LIT labeling is carried out by us using a pair of C13/C12 based
isotopic tags.
Since SILAC labeling is carried out at very early cell growth stage,
the differentially labeled cells can be combined before cell lysis and
protein isolation. So variation introduced during protein isolation
steps can be eliminated. However, SILAC method is not suitable for
tissue or blood samples. Some cell lines are also
difficult to grow in SILAC. The high cost of SILAC media is sometimes a
concern too. LIT method with its capability to label tissue, blood as
well as cultured cells is complement to SILAC. The cost of LIT labeling
may also be lower compared to
SILAC media.
Reference: details of SILAC labeling
technique can be found in following publication:
Blagoev, B., Kratchmarova, I., Ong, S. E., Nielsen,
M., Foster, L. J. and Mann, M,. A proteomics strategy to elucidate
functional protein-protein interactions applied to EGF signaling.
(2003). Nature Biotechnology. 21, 315-318.