title: Assay of antibody to group A streptococcal carbohydrate by enzyme-linked immunosorbent assay.
abstract: An indirect enzyme-linked immunosorbent assay system for determination of antibody levels to the group A streptococcal cell wall carbohydrate antigen is described. Optimal conditions for antigen preparation, purification, and conjugation to poly-L-lysine for adequate adsorption to the solid phase are presented. Antibody titers of unknown sera were determined by comparison to known reference standard pool sera. A highly significant correlation (p less than 0.0001) was found between enzyme-linked immunosorbent assay antibody titers and antigen-binding capacity in a previously described radioimmunoassay. Utilizing an isotype-specific anti-immunoglobulin reagent and immunoabsorbent-purified antibody to group A streptococcal cell wall carbohydrate antigen, we were able to detect nanogram quantities of antibody by the enzyme-linked immunosorbent assay technique. This system will provide for more generalized use of group A streptococcal cell wall carbohydrate antigen antibody determinations for the study of immune responses after streptococcal infections and their complications.
mesh_terms: D000469:Alkaline Phosphatase / Q000276:immunology; D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000276:immunology; D002241:Carbohydrates / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D011863:Radioimmunoassay; D013297:Streptococcus pyogenes / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D002241:Carbohydrates; D007074:Immunoglobulin G; D000469:Alkaline Phosphatase