Serogrouping single colonies of beta-hemolytic streptococci with achromopeptidase extraction

Achromopeptidase (TBL-1; Wako Chemicals, USA, Inc., Dallas, Tex.) prepared as a 2,000-U/ml solution will extract the serogroup antigens from single colonies of groups A, B, C, F, and G streptococci in 1 min at room temperature. This enzyme extraction is not effective for the serogrouping of all group D streptococcus species. Achromopeptidase extracts can be used with latex or coagglutination reagents.