Use of a low pressure liquid chromatography system for haemoglobinopathy screening

A closed low pressure liquid chromatography system (LPLC) is described which is suitable for haemoglobinopathy screening. The system (Glycomat) was originally developed for the quantitation of the glycated haemoglobin (HbA1). The same biochemical principles have been applied to the separation of haemoglobin A2 (HbA2) and haemoglobin variants. The instrument offers three modes of use including a fast haemoglobin elution, a variant screen and a HbA2 assay for thalassaemia screening. The fast screen isolates all of the common haemoglobin variants except HbE which elutes with HbA. This mode is a more rapid alternative to the Sickledex test. The variant screen produces a wider separation of abnormal variants giving an identification and quantitation for each. The HbA2 assay separates this minor fraction from all other haemoglobins giving an accurate percentage. Abnormal variants are also separated. To validate the HbA2 assay 252 samples were assayed by the cellulose acetate electrophoresis/elution method and LPLC with a correlation of 0.932. The system provides an accurate and sensitive alternative to traditional manual chromatography and electrophoresis methods. The automated sampler allows batches from 1-99 samples to be processed with significant savings in operator time.