[Histonet] molds for RE: floating petri dish snap freezing question

[Gayle Callis]

Kristen,

I think other plastic molds work just as well with this particular freezing 
setup.   We snap freeze mouse heads (huge!) using Peel away molds (bigger 
and deeper) with this method, no problems.  We like Tissue Tek plastic 
molds only because the plastic is thinner, less stiff.  With the Liq N2 
canoeing petri dish, you can use glass coverslip, put OCT on coverslip, 
embed tissue and let it freeze, to remove tiny block, warm back of glass 
slightly!!!!  Peggy Wenk taught this one,  clever lady!  Plastic coverslips 
are available, and with canoeing petri dish, very easy snap freezing.

Good thing you experienced the interface problem before embarking on whole 
study - I  chopped blocks and ruined some precious tissues, usually when 
someone else did the freezing and not aware of this problem.  Rules became, 
if you snap freeze, you cut your own blocks!!!

Gayle

At 10:46 AM 5/11/2005, you wrote:
>That does help. Thanks!
>
>I was afraid that if I put the tissue too close to the bottom of the mold,
>it would be affected somehow or other. I don't think our plastic molds are
>Tissue Tek (you mentioned other brands being too thick), but an H&E section
>from one of the samples I froze yesterday seems to be okay. Hoping they
>continue to be okay...
>
>I like this technique. It's very easy.
>
>"you do not want an interface of two OCT layers, they will snap part during
>sectioning at
>times." Yeah, tried that when I was experimenting. Not good! Haha. They
>popped apart as soon as I got it out of the mold. Good thing I tried that
>practicing before putting real tissue in there.
>
>Thanks again! You're just a wealth a info!
>
>Kristen