Type ACarries the A antigen; its plasma has anti-B antibodies.
Type BCarries the B antigen; its plasma has anti-A antibodies.
Type ABCarries both antigens; its plasma has neither antibody.
Type OCarries neither antigen; its plasma has both antibodies.
A antigenA marker on the red cells of types A and AB.
B antigenA marker on the red cells of types B and AB.
Anti-B antibodyFound in the plasma of types A and O.
Anti-A antibodyFound in the plasma of types B and O.
Rh factor 5
Rh positiveRed cells that carry the D antigen.
Rh negativeRed cells without the D antigen.
D antigen (Rh factor)Also called the Rh factor; blood with it is Rh positive.
O negativeNo A, B or D antigen on its red cells.
AB positiveCarries the A, B and D antigens.
How this list was compiled: Every statement checked on 2026-10-01 in at least two of these. (1) MedlinePlus, US National Library of Medicine, Blood typing, https://medlineplus.gov/ency/article/003345.htm . (2) NHS Blood and Transplant, Blood types, https://www.blood.co.uk/why-give-blood/blood-types/ (the table of antigens on the red cell and antibodies in the plasma for each group; the D antigen). (3) American Red Cross, Blood types, https://www.redcrossblood.org/donate-blood/blood-types.html (the Rh factor, the eight common types, O negative as the universal red cell donor). (4) Wikipedia, ABO blood group system, Rh blood group system and Blood type, https://en.wikipedia.org/wiki/ABO_blood_group_system . Licence: own work
The drawing: Own chart from plain geometry, 2026-10-01; nothing traced. Licence: own work
How it works
The chart shows the four ABO blood types side by side. Each column has one red blood cell with its antigens and, in the box below, the antibodies in that plasma. A second chart adds the Rh factor.
Read the full guide
Reading the chart
The letter of a blood type names the antigen on its red cells: A, B, both (AB) or neither (O). The plasma holds antibodies against the antigens its own cells lack. So type A plasma has anti-B, type B has anti-A, type O has both and type AB has none.
Positive and negative
The plus or minus sign is the Rh factor, also called the D antigen. Red cells that carry it are Rh positive; cells without it are Rh negative. With the four ABO types, that makes the eight common blood types.
The antibody always has the other letter: A cells go with anti-B, B cells with anti-A.
Questions and answers
What antigens and antibodies does each blood type have?
Type A has the A antigen and anti-B antibodies. Type B has the B antigen and anti-A. Type AB has both antigens and neither antibody. Type O has neither antigen and both antibodies.
What does Rh positive mean?
The red blood cells carry a protein called the Rh factor, or D antigen. Blood without it is Rh negative. The sign is written after the ABO letter, as in A+ or O−.
Why is O negative called the universal donor?
O negative red cells carry no A, B or D antigen, and blood services call it the universal red cell donor type. This chart is for class. It is no guide to a transfusion.
Is this the art labeling activity the four ABO blood types?
No. That is a publisher's homework title. This chart is our own and shows the same four types with their antigens and antibodies, so you can practice here. We have no answer key for any activity.