Reappraisal of an Auto Analyzer Haemagglutination System for Anti‐D Quantification

In this study various parameters for the AutoAnalyzer haemagglutination circuit of Rosenfield, Szymanski & Kochwa were re‐examined. Details are given of modifications to this circuit that improve its sensitivity and the reproducibility of results. For the quantification of anti‐D, triplicate tests done on successive days were reproducible within ± 6 %, but single tests showed a variation of ± 12 %. The anti‐D estimates obtained with certain anti‐D sera were phenotype dependant; that is, they varied according to the Rh phenotype of the test cells. It follows that in inter‐laboratory trials the Rh phenotype of the test cells should be the same in all laboratories. The need for an international anti‐D primary standard from which individual working standards may be calibrated is also stressed.