Isoelectric focusing of spectrin components in hereditary spherocytosis.

1. By isoelectric focusing in 8 M urea, spectrin purified from normal human erythrocytes was resolved into 12 to 15 peptide bands differing by their isoelectric point. Most of them were focused between pH 6.4 and 5.2, one at pH 8.7 and some minor components between pH 7.4 and 6.8. 2. The results were not influenced by the erythrocyte population age. 3. Spectrin purified from erythrocytes of five patients with hereditary spherocytosis gave similar isoelectric focusing patterns, with the exception of the lack of the pH 8.7-focused component in two related patients.