People with type o blood are considered "universal donors" meaning that all other blood types can use their blood in a transfusion. Why is this possible! Persons with type o blood produce both anti-A and anti-B antibodies.
Persons with type o blood have both A antigen and B antigen on the surfaces of their erythrocytes.
Persons with type o blood produce no anti-A or anti-B antibodies.
Persons with type O blood have no A antigen or B antigen on the surfaces of their erythrocytes.