Radioimmunoassay of 13, 14-dihydro-15-keto-prostaglandin F2alpha

A simple method is described for the determination of 13, 14-dihydro-15-keto-prostaglandin F2alpha (PGFM), using a highly specific antiserum raised in New Zealand rabbits. It involves extraction of human peripheral venous plasma with diethyl ether after addition of tritiated PGFM and HCl. Radioimmunoassay is performed on appropriate aliquots; after 2 hours or overnight equilibration the bound and free metabolite are separated using dextran-coated charcoal. The mean values +/- S.D. obtained are as follows: healthy males 32 +/- 16 pg/ml, females during follicular phase 48 +/- 18 pg/ml, luteal phase 37 +/- 8 pg/ml, first trimester of pregnancy 66 +/- 33 pg/ml, second trimester 67 +/- 42 pg/ml and third trimester 72 +/- 26 pg/ml.