A simple protocol for the subcellular fractionation of skeletal muscle cells and tissue

We describe a method for subcellular fractionation of mouse skeletal muscle, myoblast and myotubes to obtain relatively pure fractions of nuclear, cytosolic and mitochondrial compartments. Fractionation allows the analysis of a protein of interest (or other cellular component) based on its subcellular compartmental distribution and can also generate molecular information about the state of a cell and/or tissue and how the distribution of a protein may differ between different cellular compartments, tissues or cell types, in response to treatments or ageing.

The described method was specifically developed for skeletal muscle and proliferating/differentiated muscle cells. The purity of the different fractions, representing the cytoplasmic, mitochondrial and nuclear subcellular compartments was validated by western blot analysis of "house-keeper" marker proteins specific for each cellular compartment.

This low cost method allowed the mitochondrial, cytoplasmic and nuclear subcellular compartments from the same starting muscle samples to be rapidly and simultaneously isolated with good purity and without the use of an ultracentrifuge. This method permits samples to be frozen at -80°C for future analysis and/or additional processing at a later date.