As an AB blood donor, you have a unique opportunity to enhance your generous “gift of life”. People with AB Negative (.6% of the population) and AB Positive (3.4%) are potential universal plasma donors. You may not know, but there is a special need for AB Plasma. In addition to being the most rare blood type, AB Plasma is universal and can be used for all patients regardless of their blood type. Plasma is used to treat clotting disorders, burn, and shock victims.