[Histonet] Folding/pinching in GI tissue

[Angela Lamberth]

Hello everyone, I can't find any reference to this particular artifact.
There was a post from 2006 about it but no replies. I'm seeing numerous
vertical folds or "pinches" in mouse GI tissue. The ffpe blocks have 3
strips and the artifact is not necessarily seen in all of the tissue; one
GI strip might look beautiful under the scope and the remaining 2 (in the
same block) will have these folds. One day everything will look flawless
and other days (like today) many slides will exhibit this folding.

I call them vertical folds because they are oriented in the direction of my
cutting. Ribbons look great on the waterbath. I've tried preemptively
"teasing" the sections with my forceps but that doesn't seem to help.
Waterbath is 42C and sections are 4um. Blocks are nice and cold. I've tried
increasing waterbath temp to 45 and floating sections for 20-30 seconds. I
even tried slowing my cutting pace with this batch hoping that might make a
difference. I'm really frustrated to keep seeing this under the microscope
and slightly embarrassed that it keeps happening.

What's really going on here and what more can I try? I've uploaded a pic
(mouse ileum) to imgur for a visual reference. I took it with my iphone so
it's not focused well but you'll be able to see what I'm talking about.

https://imgur.com/a/IXoJG

-- 
Angela Lamberth
Histology Technician III
Histology Core Lab
La Jolla Institute for Allergy & Immunology
9420 Athena Circle
La Jolla, CA 92037