title: Excess antibody immunoassays for rat glandular kallikreins. Measurement of kallikrein from different organs in the presence of cross-reacting antigens.
abstract: An immunoradiometric assay has previously been developed for measurement of rat glandular kallikrein. In the present paper, further studies on the specificity and sensitivity of the method are described. Problems of interference of immunologically cross-reacting antigens were overcome by proper preabsorption of the antibody. A method was thus established in which enzymatic activity of the immunoreactive kallikrein could be measured even in the presence of enzymes sharing immunological determinants and substrate specificity with kallikrein. Two variants of the immunoradiometric assay have been evaluated. A simplified version with simultaneous addition of all reagents gave results equal to those obtained in the original assay. A further modification with delayed addition of the solid-phase antibody, gave considerable improvement in assay sensitivity.
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D001666:Binding Sites, Antibody; D003429:Cross Reactions; D004950:Esterases / Q000276:immunology*; D007124:Immunoenzyme Techniques; D007610:Kallikreins / Q000032:analysis* / Q000276:immunology / Q000652:urine; D007668:Kidney / Q000032:analysis; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D013363:Submandibular Gland / Q000201:enzymology*
chemical_list: D004950:Esterases; D007610:Kallikreins