Objective    To establish a soluble expression of recombinant survivin in E. coli

and evaluate the role of anti-survivin in tumor diagnosis.     Methods    The recombinant survivin was screened by ampicillin resistance

identified by PCR and double digestion of endonucleases. The sequenced DNA of survivin was analyzed by BLAST. The survivin/Trx fusion protein expressed in E.coli BL21 (DE3) was induced with IPTG

identified by Western blot and purified with Ni-NTA agarose respectively. The anti-survivin antibodies in serum were detected with an indirect ELISA. By the methods above

144 serum samples from cancer patients and 300 serum samples from normal subjects were analyzed. Meanwhile

the joint detection of anti-survivin

AFP

CEA

CA199

CA125 in blood sera from cancer patients was detected.     Results    After PCR and double digestion with endonucleases

the survivin gene was inserted into the prokaryotic expression vector PET 32a(+). After DNA sequencing

the constructed expression plasmid was transformed into competent cells E.coli BL21(DE3). Western blot identified that the recombinant survivin/Trx fusion protein was specific against survivin antibody. The purity of the protein was over 96% after purified by Ni-NTA agarose. Anti-survivin was expressed in the sera of different cancer patients

but the positive rate varied.     Conclusion    Prokaryotic expression plasmid PET 32a(+)/survivin was successfully constructed and highly purified survivin/Trx fusion protein was obtained. The detection results of anti-survivin

AFP

CEA

CA199

CA125 in blood serum show in the diagnosis of tumors

the joint detection can overcome the shortfall of each gene and enhance the diagnostic rate.