The place of capillary electrophoresis techniques in screening for haemoglobinopathies

Capillary zone electrophoresis (CZE) methods are new laboratory diagnostic tools. The screening of haemoglobin (Hb) variants by a battery of two automated CZE methods at alkaline and acid pH, followed by micellar electrokinetic capillary chromatography (MECC), has been evaluated.

Three hundred and ninety-two patients' samples with an abnormal haemoglobin fraction, detected either by isoeletric focusing (IEF) or by automated cation-exchange exchange high-performance liquid chromatography (automated HPLC), were tested by both CZE methods. Their performances were compared with IEF and automated HPLC techniques. The place of MECC has been evaluated.

Using both CZE methods, the clinically relevant variants (HbS, HbC, etc.) as well as 15 of 20 clinically silent variants tested were separated from HbA. Using the alkaline CZE method, a presumptive identification of Hb Bart's, HbH and Hb Constant Spring was obtained. Complementary testing by MECC has demonstrated it to be an aid in distinguishing the globin chain mutations before confirmation by DNA or protein structure analysis.

Using only one device, alkaline CZE, acid CZE and MECC methods offer high resolution, automated sampling and rapid analysis. They are good tools for screening of haemoglobinopathies and can replace conventional techniques.