Practical method for determination of the U status of S-s- erythrocytes.

Red blood cells (RBCs) lacking S and s blood group antigens are classified as S-s-U- or S-s-U+var but the classification may vary due to the characteristics of anti-U and to the technique used. Tests on RBCs known to lack glycophorin B (GPB) or to possess an altered form of GPB showed that polyethylene glycol-indirect antiglobulin testing or MicroTyping Systems (MTS)-gel techniques can be used as a simple and reliable way to detect RBCs with variant forms of GPB. This approach can be important in the selection of rare RBCs for transfusion to patients with undifferentiated anti-U.