An evaluation of the Bio-Rad Variant Haemoglobin Testing System for the detection of haemoglobinopathies.

The Bio-Rad Variant Haemoglobin Testing System is an automated analyser which uses the principle of cation exchange high performance liquid chromatography. This evaluation was undertaken to examine the effectiveness of the instrument as a screening mechanism to assist in the diagnosis of haemoglobinopathies. The ability to quantify haemoglobins A2 and F and to 'flag' other haemoglobin variants was tested. Within-batch precision was excellent and between-batch precision was good. Linearity and sensitivity compared favourably with the manufacturer's published ranges. The level of carry-over for haemoglobins F, S and A was less than 0.25%. The mean carry-over for haemoglobin A2 was 2.08%. This higher figure reflected the smaller absolute difference between the high and low samples for this parameter. The instrument never failed to indicate the presence of an abnormal haemoglobin in 271 selected samples. The instrument was reliable throughout the evaluation and at no time was a run aborted.