[Histonet] Re: processing v-e-r-y tiny samples

[Johnson, Teri]

Andi,

We process E7.0 mouse embryos and have problems sometimes because they are so very tiny and fragile. We've wrapped them and sometimes (but not all the time) had them break and flatten. Usually we use the histoscreen cassettes. They still will sometimes break apart using these but we have our best luck using them. You might find, though, that even with the mesh, the diameter of the holes may be big enough to let the sample pass through if the gut samples are as small as you say.

We tried the cell saver mesh inserts and they were a disaster. Lost the sample in them. I won't use them for our embryo work.

As for the histogel or agar, we've had difficulty using either in our paraffin processing. Recent histonet emails reveal other folks having a problem with the stuff randomly getting hard and brittle, like plastic and ruining the sample for sectioning. We may have 4 or 5 blocks, all go through the processor together, and one might have the problem of turning brittle. According to the other emails, Richard Allan folks hadn't any clue as to what was happening or how to fix it. And I'm clueless as well. Wish I knew how to consistently process things without this happening. Pre-embedding in a matrix like this would be so very helpful to allowing us to manipulate and properly orient tiny, fragile samples.

Good luck, and let us know what you come up with!

Teri Johnson, HT(ASCP)QIHC
Managing Director Histology Facility
Stowers Institute for Medical Research
1000 E. 50th St.
Kansas City, MO 64110