QUANTITATIVE 2-SITE ENZYME-LINKED IMMUNOSORBENT ASSAYS FOR INHIBIN-A,ACTIVIN-A AND ACTIVIN-B

We have developed three specific enzyme-linked immunosorbent assay (EL ISA) formats which quantitate inhibin A in conditioned media and serum . The assays are sensitive in a range 0.078-5.0 ng/ml and have been ch aracterized in terms of cross-reactivity to inhibin related proteins. The CK:CK assay format recognizes inhibin A, inhibin B and inhibin-rel ated molecules, while the 9A9:CK assay format recognizes inhibin A and inhibin A precursors, but not free alpha-subunit. The 11B5:CK assay a ppears to recognize only mature 32 kDa inhibin A. Additionally, we hav e developed separate, specific ELISA formats which quantitate activin A and activin B. The assays have a range of 0.2-50 ng/ml and 0.4-50 ng /ml for activin A and recombinant activin B, respectively. These assay s are presently being used to examine the concentration of inhibin A, activin A and activin B in clinical serum samples.