native human pregnancy zone protein ( pzp ) , a close homolog of alpha 2-macroglobulin ( alpha 2m ) , can be obtained in approximately 20 % yield from pooled late pregnancy plasma or serum by a combination of polyethylene glycol precipitation , euglobulin precipitation , deae-sephacel chromatography , zinc-chelate affinity chromatography , and negative affinity chromatography on insolubilized antibodies against human serum proteins .
C0032105
plasma
C0229671
serum