Evaluation of a new blood grouping instrument

A fully automated blood grouping machine, that has recently been introduced was evaluated. The instrument incorporates bar-coded sample identification and a laser scanning device to eliminate potential sample/result errors. A microprocessor interprets results, thus eliminating subjective interpretation. Ninety-seven percent of the 17,549 samples tested were correctly grouped. One-third of the initially rejected samples were correctly grouped upon retesting. The laser scanner failed to read 239 labels (1.6%). Of the original samples tested, 72 were Du positive as detected by manual methods and the automated grouper recognized 33 percent of them as Rh positive. By reducing the percent light transmission affecting Rh discrimination, it was possible to increase the percentage recognition of Du variant samples but it did not detect all. The apparatus is fitted with small diameter tubing and reagent consumption was 30 to 35 percent less than with previously available similar machines. Additional reagent savings were realized if diluted manual reagents were used. Our evaluation of the instrument has shown it to be highly accurate and reliable.