Quantitation of minor red cell populations using the single-channel autoanalyzer

An automated hemagglutination technique has been applied to the quantitation of the size of minor red cell populations. By choosing an antibody to an antigen present only on the minor population, it was possible to estimate the size of the minor population by measuring the antibody following incubation with the red cell mixture. The size was directly proportional to the amount of antibody consumed and was calculated from a regression plot established from standard mixtures. With this method, it was possible to detect minor red cell populations as dilute as 1:5000.