title: The relationship between M-antigen and opacity factor in group A streptococci.
mesh_terms: D000941:Antigens / Q000032:analysis*; D001426:Bacterial Proteins / Q000032:analysis*; D001769:Blood; D002473:Cell Wall / Q000032:analysis; D011232:Chemical Precipitation; D002845:Chromatography; D004589:Electrophoresis, Disc; D005779:Immunodiffusion; D008970:Molecular Weight; D000644:Quaternary Ammonium Compounds; D013291:Streptococcus / Q000032:analysis* / Q000276:immunology*; D013431:Sulfates
chemical_list: D000941:Antigens; D001426:Bacterial Proteins; D000644:Quaternary Ammonium Compounds; D013431:Sulfates