Classification of pathogenic streptococci into group A, B, C, D and G is based on
Hemolytic streptococci were classified by Lancefield serologically into groups based on the nature of a carbohydrate (C) antigen on the cell wall. These are known as Lancefield groups, twenty of which have been identified so far and named A-V (without I and J). Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 211
Color of colonies on blood agar
Antigenicity of cell wall carbohydrate
Presence or absence of capsule
Presence or absence of M protein
Bacteriology