The Measurement of Haemoglobin A1c by isoelectric focussing in diabetic patients

Incubation in vitro of human red cells in increasing glucose concentrations results in a rise in both haemoglobin A1c levels and an intermediate band when measured by an isoelectric focussing method. There are strong correlations between blood glucose levels, levels of haemoglobin A1c and the intermediate band both in vitro and in blood samples taken from diabetic patients. As the intermediate band is also included in the measurement of haemoglobin A1c by the usual analytical methods, this may lead to inaccurate results.