OBJECTIVETo analyze the proteomic components of the sera from the patients with hepatocellular carcinomas (HCC), in search of the diagnostic markers of HCC.

METHODSImmobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2DE), silver staining, PDQuest 2DE analysis software, peptide mass fingerprint based on matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching, were used to separate and identify the proteome of the sera from the patients with HCC.

RESULTSThe 2DE images were analysed by PDQuest 2DE software. The average matching rate was 70.2%. In IEF direction, the average deviation was (1.02 +/- 0.22) mm, in SDS-PAGE direction, the deviation was (0.97 +/- 0.14) mm. The twenty-three different protein spots were incised from silver staining gel and digested in-gel by TPCK trypsin. 15 peptide mass fingerprints (PMF) maps were obtained by MOLDI-TOF-MS. The typical peptide masses were searched in the SWISS-PROT database using PeptIdent software.

CONCLUSIONSGood reproducibility could be obtained by applying immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2DE) to separate and identify the proteome in serum. There is still the problem of efficiently removing a higher level of proteins and lipids from the serum. Identification by MOLDI-TOF-MS peptide mass fingerprint provides useful information for screening diagnostic markers of human HCC.