A total of 98.7% of streptococci, groups A,B,C, and G, isolated from various sources was correctly identified by the co-agglutination technique. The active components in this technique are protein A-containing staphylococci coated with antibodies specific for group A,B,C, and G streptococci. A suspension of streptococci belonging to one of these four groups co-agglutinates with the antibody-sen...
