title: Sandwich enzyme-linked immunosorbent assays for the quantification of the C4 isotypes (C4A and C4B) in human plasma.
abstract: Sandwich enzyme-linked immunosorbent assays were developed to determine the concentration of the isotypes of the fourth component of human complement (C4A and C4B) in human plasma. In the case of C4A a monoclonal antibody against a common determinant of the alpha chain was used to capture the protein. The bound antigen was then detected with a biotinylated monoclonal antibody reacting exclusively with the C4A isotype, followed by peroxidase labeled avidin. For the quantification of C4B, C4B-specific monoclonal antibodies were coated onto a microtitration plate in order to capture the protein. Bound antigen was then detected with a biotinylated monoclonal antibody directed against C4 followed by peroxidase labeled avidin. The assays, which were rapid, selective and specific for C4A and C4B, respectively, provide an alternative to gel electrophoresis and blot procedures for the study of unexpressed alleles ('null alleles') at each of the C4 loci.
authors.affiliation: Institut für Rechtsmedizin, Universität Mainz, F.R.G.
authors.forename: J
authors.initials: J
authors.lastname: Chrispeels
authors.forename: S
authors.initials: S
authors.lastname: Bank
authors.forename: C
authors.initials: C
authors.lastname: Rittner
authors.forename: D
authors.initials: D
authors.lastname: Bitter-Suermann
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D003181:Complement C4 / Q000032:analysis*; D015935:Complement C4b / Q000032:analysis*; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans
chemical_list: D000911:Antibodies, Monoclonal; D003181:Complement C4; D015935:Complement C4b