Question.

Does anyone have a reliable procedure to consistently avoid wrinkles with cartilage in paraffin sections of trachea (human, mouse, rat)?

A few tips and wrinkles follow.

Answer 1.

This is what works for me most of the time. I only cut human cartilage/trachea so I don't know if the mouse/rat needs to be treated differently. I keep my water bath hot, 50 degrees C, which may be too hot for whatever paraffin you are using. I use plain paraplast. It is important that the section be thin and that the disposable knife edge is new. I never take the section from the same knife area that I used to shave into the block. First, I shave into the block to the desired depth. Then I soak the block on an ice tray that has water added. Next, I take a section from the first ribbon off the block. I let it float on the waterbath until it looks very smooth, just a matter of a quarter of a minute or maybe a little longer. This usually results in no wrinkles microscopically.

Marjorie A. Hagerty
(mhagerty[AT]emc.org)

Answer 2.

Try picking up the section on the slide (from the waterbath) and then immediately holding the slide for a few seconds on a hot plate. This has to be monitored, because too much heat on such a wet section may cause the rest of the tissue to "explode"

Louise Taylor
(179LOU[AT]chiron.wits.ac.za)

Answer 3.

I have found 1, 2, or 3 drops of the new thick Joy in the waterbath has helped with wrinkles in some of my tissue cutting experiments. Start with just one drop then add more slowly. If you get too much in it, you spend your time chasing the section around the waterbath.

[Joy is a liquid dishwashing detergent sold in N. America.]

Trisha Emry
(emry[AT]u.washington.edu)