during investigation of the absorption of group-a streptococcal antibodies from human sera by a protein a-positive staphylococcus aureus strain , we found that the complement-fixing antibodies to m-associated protein ( map ) were only partially absorbed from the majority of sera tested , although they were shown to belong to the immunoglobulin g ( igg ) class by density gradient centrifugation .
C0009498
complement
C0229671
sera