The development of over-the-counter (OTC) assays for pregnanediol-3-glucuronide and estrone-B,D-glucuronide

The development of simple tests for estrone-B,D-glucuronide (E1G) and pregnanediol-3-glucuronide (P3G) in urine is described. The haptens P3G and E1G, coupled to bovine serum albumin (BSA), were used as immunogens against which specific monoclonal antibodies were made by fusion of variants of P3.X63.Ag8.653 with spleen lymphocytes from immunized mice. When covalently bonded to gelatin or BSA and passively adsorbed to a microtiter plate, the hapten provides the solid phase for an ELISA. Peroxidase-labelled monoclonal antibody is premixed with a urine specimen and the mixture is immediately added to the plate. After a brief incubation and washing, a mixture of tetramethylbenzidine chromogen and hydrogen peroxide is added to serve as substrate and generate color. The ELISA can be used to monitor levels of E1G and P3G during menstrual cycles and provides a simple, noninvasive method which can be used in a laboratory. A similar competitive assay can be performed using colloidal gold as the label instead of peroxidase. The replacement of peroxidase by colloidal gold further simplifies the procedure and could be used as the basis for an OTC test.