THE IMMUNOLOGICAL AND BIOLOGICAL ACTIVITY OF HUMAN CHORIONIC GONADOTROPHIN IN URINE

Abstract

ABSTRACT When assayed against the International Standard for HCG the biological activity, as measured by the rat seminal vesicle method, of urines from women collected during the second half of pregnancy is lower than the immunological activity (haemagglutination inhibition reaction). Almost 100 % of the immunological and biological HCG activities were recovered from the acetone precipitates of such urines. A kaolin extract of these urines produced a partial separation of the immunological activity. About half of the immunological activity and almost all of the biological activity was recovered in the concentrate. In the supernatant, left after kaolin extraction, an immunologically active biologically inactive »HCG« was found. A urine from a woman with a hydatidiform mole was assayed by both methods. The biological and immunological activities of this urine were almost unity and the ratio of the 2 activities remained unaltered in the acetone precipitate and the kaolin concentrate made from an aliquot of this urine. The kaolin supernatant contained equal and measurable amounts of the biological and immunological activities. In conclusion the method used to concentrate the urine of pregnant women will affect the ratio between the biological activity and the immunological HCG activity.