title: Quantitative quality control of antiglobulin reagents.
abstract: Double antibody radioimmunoassays have been developed for the quantification of anti-IgG, anti-C3, anti-C3c, anti-C3d and anti-C4 antibodies and for the determination of their binding constants. Assays were undertaken on 53 polyspecific antiglobulin reagents obtained from a variety of commercial and public sources. Concentrations of anti-IgG varied from 1.2 to 12.8 micrograms/ml in commercial products and from 0.4 to 6.0 micrograms/ml in public products. Concentrations of anti-C3 and anti-C3c varied from 0.1 to 1.0 micrograms/ml in most commercial products but in public products concentrations varied by more than 100-fold from 0.02 to 6.5 micrograms/ml. Concentrations of anti-C3d varied from 0.05 to 0.7 micrograms/ml in most commercial products and from less than 0.01 to 1.3 micrograms/ml in public products. Concentrations of anti-C4 varied from less than 0.01 to 0.18 micrograms/ml in commercial products and from less than 0.01 to 0.08 micrograms/ml in public products. Mean binding constants for commercial products were: anti-IgG 6.6 x 10(9) l/mol, anti-C3 4.6 x 10(9) l/mol, anti-C3c 5.3 x 10(9) l/mol, anti-C3d 0.4 x 10(9) l/mol and anti-C4 4.9 x 10(9) l/mol. Relationships were found between results obtained in quantitative assays of specific antibodies and independently performed serological assessments of potency. Anti-IgG was present in suboptimal concentrations for agglutination in several public products and anti-C3 and anti-C3c were in suboptimal concentrations for agglutination in many public and commercial products.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D003176:Complement C3 / Q000276:immunology; D015932:Complement C3c; D015933:Complement C3d; D003298:Coombs Test; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007202:Indicators and Reagents / Q000032:analysis / Q000592:standards; D011786:Quality Control; D011863:Radioimmunoassay / Q000379:methods / Q000592:standards
chemical_list: D000888:Antibodies, Anti-Idiotypic; D003176:Complement C3; D007074:Immunoglobulin G; D007202:Indicators and Reagents; D015932:Complement C3c; D015933:Complement C3d