Reverse Phase-high-performance Liquid Chromatography (RP-HPLC) Analysis of Globin Chains from Human Erythroid Cells.

β-hemoglobinopathies are severe genetic disorders characterized either by the abnormal synthesis of the adult β-globin chains of the hemoglobin (Hb) tetramer (β-globin chains) in sickle cell disease (SCD) or by the reduced β-globin production in β-thalassemia. The identification and quantification of globin chains are crucial for the diagnosis of these diseases and for testing new therapeutic approaches aimed at correcting the β-hemoglobinopathy phenotype. Conventional techniques to detect the different Hb molecules include cellulose-acetate electrophoresis (CEA), capillary electrophoresis (CE), isoelectric focusing (IEF), and cation-exchange-HPLC (CE-HPLC). However, these methods cannot distinguish the different globin chains and precisely determine their relative expression. We have set up a high-resolution and reproducible reverse phase-HPLC (RP-HPLC) to detect and identify the globin chains composing the hemoglobin tetramers based on their different hydrophobic properties. RP-HPLC mobile phases are composed of acetonitrile (ACN) that creates a hydrophobic environment and trifluoroacetic acid (TFA), which breaks the heme group within the Hb tetramers releasing individual globin chains. Hb-containing lysates are loaded onto the Aeris 3.6-µm WIDEPORE C4 200 Å LC Column and a gradient of increasing hydrophobicity of the mobile phase over time allows globin chain separation. The relative amount of globin chains is measured at a wavelength (λ) of 220 nm. This protocol is designed for evaluating globin chains in (i) red blood cells (RBCs) obtained from human peripheral blood, (ii) RBCs differentiated from hematopoietic stem/progenitor cells (HSPCs), and (iii) burst-forming unit-erythroid (BFU-E), , erythroid progenitors obtained from human peripheral blood or cultured HSPCs. This technique allows to precisely identify the different globin chains and obtain a relative quantification. RP-HPLC can be used to confirm the diagnosis of β-hemoglobinopathies, to evaluate the disease severity and validate novel approaches for the treatment of these diseases.