Griffith typing is done for

Griffith typing is used for fuher classification of S.pyogenes, belonging to Lancefield's group A. Based on the M proteins on the cell surface, they are subdivided into M types. About 80 types of Streptococcus pyogenes have been recognized so far (types M1, M2, M3 and so on). Ref: Textbook of microbiology; Ananthanarayan and paniker's; 10th Edition; Pg: 211