title: The effect of excess antigen on the enzyme-linked immunosorbent assay of onco-placental proteins.
abstract: The time course of the antigen-antibody reaction between human chorionic gonadotrophin, pregnancy specific beta 1 glycoprotein and pregnancy associated plasma protein A and their respective immobilised antibodies has been investigated. All 3 antigens showed enhanced binding with increasing length of incubation up to a maximum value, followed by a decrease. It is suggested that the diminution in binding at high antigen concentration is caused by the solubilisation of the immobilised antigen-antibody complex and that this is promoted by the high concentration of antigen.
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000032:analysis*; D001666:Binding Sites, Antibody; D002645:Chickens; D006063:Chorionic Gonadotropin / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007700:Kinetics; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000276:immunology*; D011266:Pregnancy-Associated Plasma Protein-A / Q000276:immunology*; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D006063:Chorionic Gonadotropin; D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; C031192:oncofetal antigens; D011266:Pregnancy-Associated Plasma Protein-A