Isoelectric Focusing (IEF)
In most cases, the diagnosis of a hemoglobin disorder can be made using complementary protein chemistry methods such as isoelectric focusing (IEF) and HPLC. IEF on agarose gels separates hemoglobin (Hb) fractions and variants based on their isoelectric points. Hb A and Hb F are clearly resolved by this method. Hb C can also be distinguished from Hb E and Hb O, and Hb S from Hb D and Hb G.