Lancefield group of streptococci is based on
Carbohydrate contained in the cell wall of many streptococci forms the basis of serologic grouping into Lancefield groups A-H and K-U. The serologic specificity of the group-specific carbohydrate is determined by an amino sugar.Jawetz 23e pg: 213
M proteins
Carbohydrate ( C ) antigen on the cell wall
Bile solubility
Sugar fermentation
Bacteriology