ELECTROPHORESIS OF POLYETHYLENE GLYCOLS AND RELATED MATERIALS AS SODIUM DODECYL-SULFATE COMPLEXES

Polyethylene glycol (PEG) and polyethylene glycol derivatives are anal yzed by a modification of the sodium dodecyl sulfate-polyacrylamide st acking gel electrophoresis procedure of Kurfurst. Gels using a discont inuous buffer system but which do not have a separate stacking gel are used without loss of resolution and with less tendency to form artifa ctual multiple or distorted bands. Examination of several commercial p reparations of PEGs and PEG derivatives on such gels indicates heterog eneity other than the expected unimodal size distributions. SDS-gel el ectrophoresis of proteins or other materials in samples containing PEG s may yield gels with zones of contamination from the PEGs. Methods of reducing such contamination are suggested. (C) 1996 Academic Press, I nc.