Standardization of a simple method for the estimation of haemoglobin A2.

An improved method for the estimation of haemoglobin A2, at the same time precise, simple and cheap, is proposed. Haemoglobin A is separated from haemoglobin A2 by electrophoresis on Cellogel in discontinuous buffer at alkaline pH. The strips of cellulose acetate containing the haemoglobin fractions are completely dissolved in 80% acetic acid. The percentage of haemoglobin A2 present in each sample is calculated from the values for the spectrophotometric absorbance at 396 nm. The average percentage of haemoglobin A2 (+/- standard deviation) determined by this method was 2.31 +/- 0.37 in 51 normal subjects, and 4.64 +/- 0.53 in 29 subjects with heterozygous beta-thalassaemia.