Whole blood may be preserved for up to 21 days without losing its usefulness in blood transfusions ; an anticoagulant is added to prevent clotting. Blood plasma, the fluid portion of the blood, may be frozen and/or dried and stored indefinitely. Blood and donors are screened for hepatitis , AIDS , malaria , and other infectious diseases. The potential risk of acquiring AIDS or hepatitis through transfusions has made it a common practice among patients anticipating surgery to
bank their own blood before it is needed.
Many blood banks also have facilities for apheresis , bone marrow donations, and related procedures. Some centers save umbilical cord blood (blood that is especially rich in stem cells ) for use in treatments; however, the cost of preparing and storing such blood is much higher than that of normal blood. Sometimes parents store their newborn's cord blood at a private cord blood bank in case the child has need of it, but the use of one own's cord blood is ineffective or undesirable in many diseases where such blood is used as a treatment.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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