ISOLATION AND CHARACTERIZATION OF EARLY PREGNANCY FACTOR

Early pregnancy factor(EPF)was purified from the pooled sera of 210 pregnant women at 3-8weeks of gestation.Sera from healthy nonpegnant women used as control.The samples (G-Ⅱ,G-Ⅲ and G-Ⅳ） ob-tained from pregnant women had EPF activity but no HCG activity.Polyacrylamide gel electrophopesis showed that the amjor bands in pregnant G-Ⅲ and G-Ⅳ were at similar positions in tube gels.The results of SDS-PAGE showed 3 bands in pregnant G-Ⅳ:57.0 kD,38.0 kD and 19.0 kD.The basic active form of EPF may be a small peptide of 19.0 kD. The isoelectric points of pregnant G-Ⅳ were 6.45 and 8.20.