After fixation, tissues are not yet ready for sectioning. They require embedding in a supportive medium like paraffin wax. The paraffin embedding process involves several steps:
Dehydration: Removing water from the tissue using increasing concentrations of alcohol. Clearing: Replacing alcohol with a clearing agent like xylene, which is miscible with paraffin. Infiltration: Saturating the tissue with molten paraffin wax.
Once infiltrated, tissues are embedded in paraffin blocks, which provide a solid matrix that facilitates thin sectioning using a microtome.
