Isoelectric focusing of the human IgG light chains: a classification of the fractions and their normal values

The method of isoelectrofocusing was employed to obtain a reproducible pattern of human IgG light chain bands. The map of IF spectra, which contained 13 main fractions and some subfractions, was delineated. Isoelectric points of these fractions and their quantitative relations in 10 healthy individuals were determined. Initial studies performed in 3 patients with monoclonal immunoglobulins and in 1 patient with gastric ulcer, negative for monoclonal protein, showed significant deviations from normal values in certain fractions of the IF spectrum.