title: Lancefield extract of group A streptococci type 15 acts like an anti-human IgG with restricted specificity.
abstract: Lancefield extract of streptococci group A type 15 precipitates certain human sera and agglutinates red cells coated with some IgG anti-Rh antibodies. The frequency of precipitation varies between populations. The serum component in the precipitate is IgG. The results indicate that an iso-allotypic marker is detected by the extract.
mesh_terms: D000372:Agglutination Tests; D004903:Erythrocyte Aggregation; D006801:Humans; D005779:Immunodiffusion; D007074:Immunoglobulin G; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System; D013297:Streptococcus pyogenes / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007518:Isoantibodies; D012204:Rh-Hr Blood-Group System