Purification of EPF-like Substance from Bovine Ovum Culture Medium by DISC-Preparative Electrophoresis

We obtained the medium (IVF-OCM) which cultured bovine ova for 72 hours with TCM-lgg without serum protein after in vitro fertilization, and researched whether Early Pregnancy Factor (EPF)-like substance was able to purify simply from IVF-OCM by using DISC-preparative electrophoresis equipment. EPF activity was detected at a part of fraction purified from IVF-OCM and the protein bands of M. W. 21.5 and 66 KD was observed in its EPF positive fraction. But, all of the other EPF negative fractions had the band of M. W. 66 KD and did not have 21.5 KD band. Therefore, we thought that the band of 21.5 KD was EPF-like substance. Moreover, all of the fraction purified from the cumulus cells culture medium (CM) did not have EPF activities and the band of 21.5 KD. Therefore, EPF-like substance may be secreted from the ovum itself. These results suggests that DISC-preparative electrophoresis is an efficient method for purify EPF-like substance from IVF-OCM.