How is the blood typing concerning the ABO system and the Rh usually done?
In the blood typing for the ABO system and the Rh system a blood sample is collected from the person and three small volumes of the sample are separated and dispersed on glass laminae (slides). On the first lamina serum having anti-A antibody is dripped; on the second lamina serum containing anti-B antibody is dripped; on the third lamina serum with anti-RH antibody is dripped. If no agglutination reaction takes place in all of the laminae the blood is of type O- (universal donor); if agglutination happens only in the first lamina the blood is type A-; and so on.
There are other methods of blood typing. Blood typing must be performed by qualified technicians.