The Rh-negative donor.

By typing fully for Rh, donor samples found to be D-negative but C-positive and/or E-positive on the Kontron Groupamatic G2000, the incidence of Ccddee (r'r) was found to be 0.44%, ccddEe (r"r) 0.50% and Du 0.30%. A total of 15,000 samples typed on the Groupamatic as D-, C- and E-negative were tested by an antiglobulin technique for Du, but none was found to be positive. A new strategy was therefore adopted for routine Rh typing of donations that includes typing first-time donors on the Groupamatic for C, D and E antigens; those that type as D-negative, C-positive and/or E-positive are further tested but no routine Du testing of D-, C- and E-negative donations is performed. Donations are labelled according to their D type, and the once used terminology 'Rh-positive donor, Rh-negative recipient' is no longer used except for those rare Rh D-positive donors belonging to the D category VI of Tippett & Sanger (1962).