Analysis of hemoglobin variants using nondenaturing gel electrophoresis and matrix-assisted laser desorption ionization mass spectrometry

Molecular analysis of hemoglobin variants is crucial in the diagnosis of hemoglobinopathies. Routinely used techniques for identifying variants include alkaline gel electrophoresis and automated HPLC. Sometimes comigration of variants in electrophoresis or coelution in HPLC provides ambiguous results. Due to high sequence homology between normal and variant hemoglobin, proteomic analysis using LC/ESI-MS data is also challenging. Here we describe a novel method wherein alkaline gel electrophoresis and MALDI-MS were used in combination to characterize variant samples such as Hb FSD and Hb D-Iran unambiguously. The method is rapid, efficient, and cost effective. In the future, it can be applied as a diagnostic tool.