Serological distinction of A antigen between red blood cells and saliva in blood grouping of blood and body fluid stains.

A antigens of red blood cells and body fluids such as saliva, semen and sweat could be serologically distinguished using rabbit or guinea pig immune anti-A. As for antisera specific for red blood cell A, A+ rabbits were intravenously immunized with A group red blood cells. The resulting antisera were absorbed with O and B red cells and with A. Se saliva. The absorbed anti-A reacted with A red cells (titer 1:32) and was not inhibited with A. Se saliva. Guinea pigs were intramuscularly injected with A. Se saliva. Crude antisera contained agglutinins to human red cells which were abolished by absorption with A red cells. After absorption with O. Se saliva, the antisera were proved to have agglutinin activity with A group saliva using latex coated with A. Se saliva. A antigens from blood or body fluid stains could be distinguished by the elution method with these anti-A sera.