AFFINITY CHROMATOGRAPHIC METHOD FOR THE EXTRACTION OF OCYTOCIN FROM HUMAN AND RAT PLASMA

A procedure based on affinity chromatography for the extraction of ocy tocin is described. Ocytocin antibody, covalently attached to a magnet izable iron suspension, retains its ability to bind ocytocin from bloo d plasma. The conjugate can be reused several times. Recovery of ocyto cin was 60-70%, and the detection limit for the extraction assay was a bout 1 pg per tube. The specificity of the extraction method was chara cterized by HPLC/RIA on specimens extracted from blood plasma. The ext racted material was found to be chomatographically identical with the reference ocytocin preparation. Comparison of RIA data for the same sa mples extracted by immunoextraction (y) and adsorption (x) showed a li near regression of y = 0.83 x + 2.12, r = 0.81, n = 17.