Neonatal haemoglobinopathy screening.

The current practice of cord blood screening was found to be missing 14.3% of 'at risk' infants identified for screening in the antenatal period, largely due to failure of sample collection. The possibility of including haemoglobinopathy screening into the already established Guthrie card screening system for phenylketonuria and hypothyroidism was investigated, using haemoglobin electrophoresis on cellulose acetate membranes, citrate agar gel and isoelectric focussing in polyacrylamide gel. Denaturation of blood once dried onto filter paper made the standard electrophoresis techniques unsuitable, whilst isoelectric focussing gave clear separation of all bands and was therefore accepted as the method of choice.