Enhanced electrophoretic separation and resolution of myosin heavy chains in mammalian and avian skeletal muscles.

We report a sodium dodecyl sulfate-polyacrylamide gel electrophoresis protocol for the reliable separation, with high resolution, of myosin heavy chain isoforms in adult avian (chicken) and mammalian (mouse) skeletal muscles. The sample preparation time can be relatively short, thereby minimizing endogenous proteolytic activity which may otherwise result in dispersed and spurious bands. Inclusion of 2-mercaptoethanol in the upper electrode buffer greatly improves band resolution. Glycerol is commonly included in the reported protocols for myosin heavy chain separation and our results demonstrate that the concentration of glycerol employed can have a marked effect on the relative order of migration among myosin heavy chain isoforms.