Use of a modified procedure for treating small amounts of red blood cells with 2-aminoethylisothiouronium bromide.

Kell null red blood cell samples can be prepared using 2-aminoethylisothiouronium bromide (AET). This article describes a modification whereby only three drops of a 5% red blood cell suspension may be AET treated. This procedure has been used routinely in the authors' laboratory for more than a year. One patient's serum contained anti-Kpb plus anti-C and anti-D. Tests with panel cells pretreated with AET made it possible to identify underlying Rh antibodies without using a panel of genetic Kpb negative red blood cells. Of 24 red blood cell eluates from patient sample with warm autoantibodies, one had specificity within the Kell blood group system. This small volume AET-treatment method is a quick screen for the differentiation of a Kell-related specificity from a non-Kell specificity of both warm autoantibodies and alloantibodies to high-incidence antigens.