Organization that collects, stores, processes, and supplies blood .
Most blood donations are separated into components, which can be frozen and stored longer than whole blood and used by multiple patients. In hemapheresis, large amounts of one component can be separated from a single donor's blood and the rest returned to the donor. Before World War I, a physician had to find a compatible donor and give an immediate blood transfusion . Safe storage of blood and its components made possible innovations such as heart-lung machines.