Human and rat serum proteins, lipoproteins, ammonium persulfate, gel concentration, and disc electrophoresis

Abstract

Abstract Since the presence of residual ammonium persulfate in polyacrylamide gels has been reported to cause artifacts in electrophoretic patterns of certain proteins, extensive electrophoretic experiments were conducted with human and rat serum proteins and lipoproteins. These experiments included substitution of riboflavin and light as a catalyst for ammonium persulfate at several gel concentrations, removal of ammonium persulfate from the gel by preliminary electrophoresis, and incubation of serum proteins and isolated lipoproteins with ammonium persulfate prior to electrophoresis. The riboflavin catalyzed gels were much softer and were of larger pore sizes than ammonium persulfate catalyzed gels of the same acrylamide concentration and, therefore, the elecerophoretic patterns in the two gel systems were different. However, differences were not observed when the ammonium persulfate was was removed by preliminary electrophoresis. Similarly, incubation of samples with ammonium persulfate did not produce spurious bands and, thus, established that ammonium persulfate does not produce artifacts during disc electrophoresis of serum lipoproteins and proteins using the pH 9.5 system.