INTRODUCTION: To purify or characterize an intracellular protein, it is important to choose an efficient method for disrupting the cell or tissue that rapidly releases the protein from its intracellular compartment into a buffer that is not harmful to the biological activity of the protein of interest. One of the most widely used methods for disrupting soft tissues is homogenization. This protocol describes three processes for homogenization of animal tissues using mechanical shear: a Potter-Elvehjem glass-Teflon homogenizer, a Dounce hand homogenizer, or a handheld Waring Blendor. These methods are rapid and pose little risk to proteins other than the release of proteases from other cellular compartments. Proteolytic degradation can be minimized by the inclusion of protease inhibitors in the homogenization buffers. An optional procedure to remove mucin from tissue homogenates is also presented.