Formal Name: ABO Group and Rh Type
What is Rhesus factor tested?
Rhesus factor is a characteristic of an individual’s blood. Rh factor is present on the surface of the red blood cells (RBCs). This is a protein chain. If your blood contains the factor, then you are Rh positive. If there is no protein in the RBCs’ surface, you are Rh negative. Rh factor is determined by your ancestry lineage, meaning the factor is passed from parents to their children via genes. Rhesus factor is also important if there are any abnormalities after transfusion of blood.