A physician who specializes in blood banking/transfusion medicine is responsible for the maintenance of an adequate blood supply, blood donor and patient-recipient safety and appropriate blood utilization. Pre-transfusion compatibility testing and antibody testing assure that blood transfusions, when indicated, are as safe as possible. This physician directs the preparation and safe use of specially prepared blood components, including red blood cells, white blood cells, platelets and plasma constituents, and marrow or stem cells for transplantation.