Tissue fixation is performed by chemical fixation using formalin. This prevents the postmortem degeneration of the tissue and hardens soft tissue. The tissue is dehydrated using ethanol and the alcohol is cleared using an organic solvent such as xylene. The tissue is embedded in paraffin which infiltrates the microscopic spaces present throughout the tissue. The embedded tissue is sliced using a microtome and subsequently stained to produce contrast needed to visualize the tissue.