Km (1) [Inv (1)] typing of saliva and semen

Km(1) [formerly called Inv(1)] typing of 115 matched serum and saliva samples and of 31 matched serum and semen samples is reported. The use of freezing and thawing to reduce the viscosity of the saliva, which would otherwise cause non-specific aggregation of the red cells used in the test, is described. Problems of antiserum selection and of semen and saliva samples which do not respond to the freezing and thawing treatment are discussed.