The Reliability of Molecular Weight Determinations by Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

Forty proteins with polypeptide chains of well characterized molecular weights have been studied by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate following the procedure of Shapiro, Vinuela, and Maizel (Biochem. Biophys. Res. Commun., 28, 815 (1967)). When the electrophoretic mobilities were plotted against the logarithm of the known polypeptide chain molecular weights, a smooth curve was obtained. The results show that the method can be used with great confidence to determine the molecular weights of polypeptide chains for a wide variety of proteins.