Frozen section guide from Northwestern University and others
Frozen sectioning is the method of choice when paraffin processing may interfere with any downstream techniques. Common examples include Oil Red O staining for lipids (removed during paraffin processing) and antibodies whose epitopes are masked or destroyed by the ethanols and xylenes and heat involved with paraffin processing.
- Tissue should be trimmed to specified region and cleaned of fat. Dab gently to remove any excess buffer.
- Embed in OCT and freeze in a dry ice/isopentane slurry- see Northwestern guide.
- Store frozen blocks at -80° and transport to lab on dry ice.
- Fresh 4% Paraformaldehyde (PF) – perfuse animal or place harvested tissue in fixative immediately. 10% NBF is also OK when fresh PF is not available.
- Fixation times will vary depending on tissue and antigen of interest. Perform initials tests before full scale experiments.
- Core can provide 30% sucrose to cryoprotect fixed tissues then embed and freeze for you.
Cryosectioning (Frozen Sections)
- Tissues will be cut at 5 microns unless otherwise indicated on form.
- One section per slide unless otherwise requested.
- Sections are placed on Superfrost/Plus slides (charged).
- Bring your own slide boxes or purchase from Core. Return to slide boxes for credit on future submissions.
- *Bring dry ice when picking up your frozen tissue and prepared slides.