Sean Lauber:Formalin Fixation & Preparation for Histology

This procedure involves fixing of lung tissue for 48 hours in 10% formalin before moving to 70% EtOH.

1. Perfuse your lungs with ample 10% formalin before placing in a labeled 15 ml falcon tube containing 8-12 ml formalin.

2. After 48 hours (24 or 72 hours is okay as well, but to be consistent always use 48 h) you can begin cutting the lungs.

3. If you're cutting the left lung, cut it with a scapel about halfway and store it in a histology cassette in 70% EtOH.

4. Store the remaining right lung in a labeled 15 ml falcon tube containing 8-12 ml of 70% EtOH indefinitely (this is fine for H&E staining but for IHC you need fresh tissue). Pour the formalin in a 500 ml container in the fume hood for disposal with vytac.

5. Fill out a histology request form and charge sheet. For basic cutting I do the following:

 Embed cut edge
 Cut at 5 um
 Cut serial sections 500 um apart
 Put 3 slices on a single slide
 Stain with H&E

6. Bring it upstairs and that's it!