Observations on the use of an autoanalyser and a manual technique for the detection of the red cell antigens C, D, E, c, K and S in bloodstains.

The results of the detection of the Rh antigens (D, C, E, c) and the S and K antigens by an elution technique comparing the AutoAnalyser and a manual method for the detection of eluted antibody are presented. Investigation of a series of anti-D sera demonstrates that while it is not too difficult to select antisera for the detection of the D antigen in fresh stains (i.e. up to 4 weeks old) some of these sera will not be satisfactory for typing older stains. The AutoAnalyser system used is low ionic strength/polybrene which has a capacity for detecting 0.002 microgram/ml of anti-D, but in spite of this degree of sensitivity the manual technique for the detection of eluted antibody compared very favourably and tended, where older stains were being tested, to give more conclusive results than the AutoAnalyser. The superiority of the manual technique was most pronounced when detecting the S and K antigens.