Radioimmunoassay of the F Prostaglandins

Abstract

Antibodies to prostaglandin F2α (PGF2α) were produced in rabbits immunized with a conjugate of PGF2α covalently linked to bovine serum albumin (BSA) by reaction with carbodiimide reagent. A radioimmunoassay was developed using dextran-coated charcoal to separate the free from antibody-bound PGF2α-3H. The sensitivity of the method was about 100 pg. Butanol was used for extraction of plasma and the various classes of prostaglandins were separated on a small silicic acid column. Recovery of PGF2α-3H through the extraction and separation procedures was 75–85%. Equilibration of PGF1α, PGE2, PGE1 PGA2 and PGB1, with antiserum and PGF2α-3H showed a progressive loss of ability to displace the labeled prostaglandin from the antibodies related to the degree of differences in molecular configuration from the hapten used in the immunization. The method should be sufficiently sensitive, precise, and simple to allow its use in the routine estimation of the F prostaglandins from biological samples.