MICROWAVE ELUTION OF RED-CELL ANTIBODIES

Using a commercial microwave oven (750 W, 2,450 MHz), we compared the use of microwave energy to the commonly used method of acid-glycine el ution (Elu-Kit II(R), Gamma Biologicals, Houston, Tex., USA) to elute antibodies from direct antiglobulin test positive red blood cells (RBC ). Using a 33% suspension of RBCs in cold saline (1-6 degrees C) in a polypropylene test tube, the microwave technique was comparable for el uting Rh (except anti-c and anti-e) and Kell and superior for eluting Duffy, Kidd antibodies while acid-glycine was superior in eluting S an d s antibodies. Consistent results were obtained using the microwave t echnique when the RBC suspension reached temperature of 57-64 degrees C. Heat or the rate of temperature rise appears to play an important r ole in the microwave elution process although other not yet identified microwave properties may also be a factor. Microwaves are a quick (8 s) alternative to well-established methods of elution and have shown t o give consistent results in our study. Commercially available microwa ve ovens vary substantially in power, making it necessary to perform a n initial calibration of the microwave in order to determine a locatio n within the microwave cavity where exposure to microwaves will consis tently achieve temperatures of 57-64 degrees C in all cell suspensions .