Preparation and characterization of the monoclonal antibody against human sp-erm protein 17

AIM: To prepare and characterize the monoclonal antibody (mAb) against sperm protein 17 (Sp17). METHODS: Human Sp17 cDNA was cloned and recombinant Sp17 protein was expressed as a fusion protein with an N-terminal 6-His tag. The purified recombinant Sp17 protein was used to immunize BALB/c mice for preparing mAb. mAb-produced hybridoma cells were screened by ELISA and the specificity of mAb was analyzed by immunohistochemical staining and blocking test. RESULTS: Two hybridoma cells (3C12 and 3D6) secreting mAb against Sp17 were developed. The isotypes of these two mAbs, 3C12 and 3D6, were IgG1 and IgM, respectively. ELISA detection showed that titers of mAbs, 3C12 and 3D6, were 1∶64, 1∶32 in cultured supernatant and 1∶1×105, 1∶5×104 in ascites, respectively. The results of immunohistochemical staining and blocking test indicated that 2 mAb specifically bound to Sp17 in human and rat testis and human ejaculated spermatozoa. Anti-Sp17 mAb also detected Sp17 in ovarian cancer. CONCLUSION: The successful preparation of anti-Sp17 mAb will be useful for assessing the native distribution and aberrant expression of Sp17 protein.