Novel aspects in the evaluation of an automated blood group analyser

In contrast to other studies evaluating machines by testing a great number of samples, we focused here on the sensitivity and on the influence of possible disturbing factors on automated blood group testing.

As the gelcards of the DiaMed-ID Micro Typing System are well known, this study examines reading and interpretation of the gelcards by the automated analyser Techno TwinStation. The results of automated reading were compared with visual reading of the gelcards taken out from the machine.

The sensitivity, tested by the titers of some complete and incomplete antibodies, was at least the same for automated as for visual reading. Samples with weak antigens were well recognised by the analyser. Mixed field agglutinations were recognised as questionable results by automated reading up to a relation of 1 : 10 for the most part. Antibody screening and reverse typing were not influenced by hyperbilirubinaemia, whereas in lipemic and haemolytic samples doubtful results were reported.

Interpretation of the results by the automated analyser Techno TwinStation may be disturbed in some difficult samples, but in most of these cases the analyser reports not a false, but a doubtful result, thus triggering visual reading by the operator.