Antigens are markers found on the surface of your red blood cells, and the combination you carry is what gives you your blood type.
• Blood Group A has the presence of Antigen A
• Blood Group B has the presence of Antigen B
• Blood Group AB has the presence of both Antigen A and Antigen B
• Blood Group O has neither Antigen A nor Antigen B
Separately, if the RhD antigen is present, you are RhD-positive (+). If it is absent, you are RhD-negative (–).
Fun fact: Each drop of blood contains 200–300 million red blood cells, and each red cell has more than a million markers on its surface.
