Demonstration of alpha 1-acid glycoprotein (orosomucoid) by double one-dimensional slab gel electrophoresis: evidence for intra- and interindividual variability of the microheterogeneity pattern in health and disease.

This double one-dimensional slab gel electrophoresis technique, in the sequence polyacrylamide gel electrophoresis followed by isoelectric focusing in polyacrylamide gels, permits the selective demonstration and comparison of the micro-heterogeneity pattern of alpha 1-acid glycoprotein (orosomucoid) in as many as 96 human plasma or serum samples on one gel. The electrophoretic analysis is performed on 8 microL of serum or plasma without prior purification. Several hundred samples can be analyzed by one investigator during a working day. Densitometric evaluation of the patterns revealed two new findings: 1) The microheterogeneity pattern can be described by a parameter that is independent of the concentration of orosomucoid in plasma: the center of density of the pattern, with the peak number as coordinate. 2) There is a considerable average shift of the center of density towards more basic components among the patterns obtained for samples from hospital patients. The results suggest that followup of the intra-individual variation of the orosomucoid pattern in health and disease might help in studying the still-uncertain function of this protein as well as the diseases affecting the pattern.