Methods: EPF was purified from 430ml human pregnancy sera. The purification scheme involved sequential DEAE 52 chromatography, SP Sepharose F. F chromatography, ConA Sepharose 4B chromatography and Heparin Sepharose C1-6B chromatography.

• 方法:从430ml早孕血清中采用柱层析方法分离纯化EPF,依次经过DEAE 52阴离子交换层析、SP Sepharose EF阳离子交换层析、ConA Sepharose 4B亲和层析和Heparin Sepharose C1-6B亲和层析。