Deparaffinization and Rehydration of Tissue Sections: A Two-step Procedure to Remove Paraffin Wax from FFPE Tissue Slides Followed by Tissue Rehydration

Overview

In this video, we demonstrate the processing of FFPE or formalin-fixed paraffin-embedded sections obtained from gastrointestinal tumor tissue. The deparaffinization and rehydration steps allow the processing of the tissue specimen for subsequent analytical applications.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national and international guidelines for human welfare and have been reviewed by the local institutional review board.

1. Washing the Slides

1. Prepare 10 µm of unstained formalin-fixed paraffin-embedded (FFPE) sections.
2. Place slides in a glass slide holder: use about 3-5 largest cross-sectional slides unless the tissue is minimal, and more slides are needed.
3. Fill the slide holder with Xylene, and make sure that all tissue on the slide is submerged. Allow to sit for 15 min.
4. After 15 min, pour out the Xylene with the slides held with a pipette tip so that the slides do not fall out.
5. Pour in more Xylene to the same level as before. Allow to sit for another 15 min.
6. After 15 min, pour out the Xylene again.
7. Fill the slide holder with 100% ethanol (EtOH), and make sure that all tissue on the slide is fully submerged. Allow to sit for 3 min.
8. Pour off the EtOH while carefully holding the slides. Refill to the same level with more EtOH. Allow to sit for 2 min.
9. Pour off the EtOH again and remove the slide. Carefully place them face up on a clean paper towel to dry. Allow to sit for 10 min.

Materials

Name	Company	Catalog Number	Comments
Xylene	Sigma-Aldrich	214736
100% Ethanol	Sigma-Aldrich	24194