Urinary trypsin-inhibitor: extraction from pregnancy urine by affinity chromatography.

Affinity chromatography has led to the extraction of a trypsin inhibitor from urines of pregnant women, with a recovery of about 85%. The inhibitor obtained by this method is fairly pure, but heterogeneous, according to several criteria. The heterogeneity is not the result of the extraction procedure, but it seems to pre-exist in the urine itself.