If your blood does not clot in the presence of either serum, then you have type O blood. Clotting that occurs when A cells are mixed with your serum indicates you have type B blood. Clotting that occurs when your serum is mixed with both types of cells indicates you have type O blood. Lack of clotting when your serum is mixed with both types of blood indicates you have type AB blood. To become a donor at the Central Florida Blood Bank, you must be at least 17 years of age , be in good health, and weigh at least 110 pounds .
Most blood banks have no upper age limit.
Whole blood can be donated once every 8 weeks. Your body replenishes the fluid lost from donation within 24 hours. It may take up to two months to replace the lost Red Blood Cells. An increasingly common procedure is apheresis , or the process of removing a specific component of the blood, such as platelets, and returning the remaining components, such as Red Blood Cells and Plasma, to the donor. This process allows more of one particular part of the blood to be collected than could be separated from a unit of Whole Blood.