A person can donate blood every two months, platelets every two weeks, and plasma twice a week. In whole blood donation, the blood is collected directly into a bag until it is used in a transfusion. In platelet donation, the platelets are separated from the other blood cells by apheresis and saved; the other blood cells and plasma are injected back into the donor. In plasma donation, blood cells are separated, plasma is removed, and the blood cells are injected back into the donor. Why could you donate plasma twice a week