The procedures to use for the typing of ABH, Rh, MNSs, Kell, Duffy, and Kidd blood group antigens are explained. The techniques for typing Gm and Km serum group antigens in bloodstains are also described. The differences in typing liquid blood and dried bloodstains are explained. Blood group antigens, agglutination, and serological procedures are detailed. The variables involved in absorption and elution and techniques for optimizing them are given. The procedures to be followed in detecting specific antigens are also explained. Sources of materials used in the tests; tables; about 225 references; and appendixes giving manufacturer's addresses, a table showing blood grouping reagent stability and storage, and a summary of elected methods and procedures are supplied.