The ABO and Rh groups in transfusion

system recipient type donor red cell type donor plasma type

ABO A A* or O A or AB

ABO B B or O B or AB

ABO O O only O, A, B, or AB

ABO AB AB*, A*, B, or O AB

Rh positive positive or negative positive or negative

Rh negative negative or positive**, *** negative or positive**

*Not if the patient's serum contains anti-A1 (antibody to common type A red cell in subgroup A patients).

**Not if the patient is a female less than 45 years old (childbearing possible), unless life-threatening hemorrhage is present and transfusion of Rh-positive blood is lifesaving.

***Not if the patient's serum contains anti-D (antibody to positive red cells), except under unusual medical circumstances.