A rapid micro-scale method for the measurement of haemoglobin A1(a+b+c)

Abstract

A rapid method is described for the measurement of total glycosylated haemoglobins (HbA_1(a+b+c). The procedure utilizes 0.05 ml of blood and takes forty minutes to complete manually. Eighty blood samples can be analysed without automation by one person in a day. Each analysis uses less than 2 mg of potassium cyanide, resulting in a method that is both safe and rapid for routine hospital laboratories. The inter-assay coefficient of variation was 4% and that for intra-assay measurements 3%, over the range 5–20% HbA_1(a+b+c). The method confirmed that the level of HbA_1(a+b+c) is elevated in imperfectly controlled diabetics. Amongst patients with blood glucose levels of less than 10 mmol/l the mean level of HbA_1(a+b+c) was found to be 8.5%; samples from 14 known diabetics gave a mean value of 10.9%, whereas 17 known non-diabetic samples gave a mean value of 8.3%. In the group of samples from 27 diabetic individuals with blood glucose levels above 10 mmol/l the mean level of HbA_1(a+b+c) was found to be 13.5%.