The use of preparatory electrophoretic methods, such as paper curtains or starch blocks, has not been particularly successful for the fractionation of mucopolysaccharide-protein complexes. Electrophoresis of these polar materials, which form viscous solutions, suffers from the same problems of slow separations and adsorption by the supporting media as do proteins (1) but to an even larger degree. The Brinkmann Continuous-Flow Electrophoretic
Separator ,3 has been successfully used for the separation of a variety of materials including serum proteins, peptides, and thymus extracts (24). In this apparatus, the separation is carried out in a layer of buffer passing between glass plates, thus alleviating the problem of adsorption of the materials being separated. This lack of supporting medium, as well as the reports (2, 3) of the separation of large quantities of proteins and peptides in a relatively short time, made it seem worth while to use the apparatus for the study of acidic mucopolysaccharides and their complexes with protein. The present report will indicate the usefulness of preparative "free-flow" electrophoresis with viscous mucopolysaccharides, and discuss the problem of maintaining the pH during the fractionation.
Methods
In the studies reported here, the Brinkmann Continuous-Flow Electtrophoretic Separator, model FF, was employed. The apparatus and its general mode of operation have been described (2, 4).