Applicability of the log MM - √D relationship to linear polyacrylamide gradient gel electrophoresis under a wide range of experimental conditions

Recently we reported about a linear correlation between the logarithm of the size of native proteins (log mol mass or log Stokes' radius) and the square root of their migration distance (‐ √D) in linear polyacrylamide (PAA)‐gradient gels (G. M. Rothe and H. Purkhanbaba, Electrophoresis 1982, 3, 33–42). The linearity between log MM and √D is not subject to time using homogeneous buffers in electrophoresis, no matter how the constants of the corresponding regression lines, slope and intercept change as a function of time. The realiability of this correlction has been re‐examined with 0.7 mm thin gel plates and extending the time of electrophoresis under non‐denaturating conditions from 2 to 95 h. It is demonstrated that the linear log size ‐ √D‐relationship is also applicable to sodium dodecyl sulfate (SDS) linear PAA gradient gel electrophoresis.