Densitometric quantitation of high resolution agarose gel protein electrophoresis.

The authors developed a cost-effective procedure for high-resolution protein electrophoresis in agarose gel which results in electrophoretic patterns that can be both visually interpreted and densitometrically quantitated. Unique features include the development of special molds for the preparation of several gels simultaneously and the combination of chemical with densitometric procedures to accurately quantitate the protein fractions in both normal and pathologic sera. Since the albumin concentrations obtained by densitometric scan of either cellulose acetate or agarose gel were erratic with respect to colorimetric (ACA) or immunochemical (ICS) measurements, the authors incorporated colorimetric measurements of albumin and total protein with densitometric quantitation of the electrophoretic bands into an algorithm for calculating protein concentrations. The densitometric quantitation of the gamma globulin fractions compared well with the sum of the immunochemically determined IgG and IgM concentrations (r = 0.98). Alpha and beta globulins were calculated using mathematically adjusted densitometric scan percentages and the total alpha and beta globulin protein concentration. The agarose gel procedure was more sensitive than cellulose acetate in the detection of paraprotein bands in a comparison of 93 sera containing paraproteins.