Blood Types: The ABO and Rhesus (Rh) Blood Typing System - How are they different (ABO blood groups), and how does blood typing work??
Surface proteins classify in our Blood Types as A, B, AB or O and presence of the Rhesus Factor (Rh or D) results in positive blood types: A+, B+, AB+ or O+. Blood Types with the absence of the Rhesus Factor (Rh) form negative blood types: A-, B-, AB- or O-.
Although there are many 'other' surface proteins on our blood cells, some that can even be classified into different biological "blood types", it's mismatches of the ABO system which causes the largest problems (transfusion reactions) in recipients of Blood Transfusions. Which is the Universal Donor, who is the Universal Recipient?