[Histonet] friable or crumbly O.C.T.

[Bill B.]

I will 2nd this. 

When I did neuropathology at a major institution, we froze all frozen sections in an isopentane slurry cooled with LN2. We waited for the OCT to warm to cryostate temps before cutting. If there was time pressure from the surgeons, I used my thumb to warm more quickly, until sections stopped falling apart. We got minimum freeze artifact with this method. 

For research we used homogenized brain (brain paste) instead of OCT which gave better sections as there was not a change in physical properties you get with OCT vs brain. 

Bill Blank, MD

At 10:40 AM -0400 8/9/10, Della Speranza, Vinnie wrote:
>I'm guessing that liquid nitrogen or dry ice temperature is too cold for sectioning OCT.
>OCT cuts well down to about -25 degrees C. 
>Liquid Nitrogen is about -160 degrees C. I believe dry ice is in the same temp range at LN2
>
>You will want to give the OCT blocks the opportunity to "warm up" to cryostat temperature before attempting to section them. Leave your frozen blocks in the cryostat for 30-60 minutes before sectioning to allow them to come to optimum temperature