ABO
Antigens & Antibodies
Ag
on RBCs
Ab
in plasma
ABO
Blood Type
A
B
A &
B
none
anti-B
anti-A, anti-B & anti-A,B
anti-A
none
A
B
AB
O
Ag = antigen
Ab = antibody
Note: the
antibodies are “naturally occurring” – that is they are present in patients plasma
without patients having been exposed to antigen.