Simplified method for recovery of autologous red blood cells from transfused patients

Separation of autologous and transfused red blood cells from recently transfused patients is necessary for the proper identification of any red blood cell alloantibody or autoantibody. We compared two methods of separation: the standard technic of microhematocrit centrifugation with phthalate ester solution, and a simplified method of microhematocrit centrifugation without the use of esters. Autologous red blood cells were concentrated in the top layer of the capillary tube by both methods. Separation efficacy was comparable, as determined by blood group antigen reactivity. Good separation was achieved only in samples drawn three or more days post transfusion. Microhematocrit centrifugation without the use of phthalate esters is a simple method for the recovery of autologous red blood cells from recently transfused patients that can be performed by any standard clinical laboratory.