SPARC binding proteins detected by mass spectrometer. Cell lysate were collected from HepG2 cells by non-denaturing lysis buffer. Total cell proteins were immnuoprecipitated by SPARC specific antibody from R&D company. SPARC and binding proteins were loaded on SDS-PAGE gel and ran for 30 minutes. The gel was stained with Coomassie Blue and SPARC-binding proteins in gel were cut and send for mass analysis for the detection of the specific proteins.