Re: Cryostat phenomenon

From:Karen Larison <>

I agree with Gayle.  This tends to happen on dry days.

We cryosection tiny zebrafish embryos.  We first embed them in a 
melted agar-sucrose matrix, which allows us to orient them very 
precisely within the block for serial sectioning.  We then let the 
block solidify and then sink it in in sucrose before sectioning.  The 
nice thing about these agar blocks is that they ribbon nicely.  You 
can cut a series of sections with the antiroll plate, then use a 
brush to straighten them out, and then pick them up.  Using this 
method, we are better able to position these tiny sections on a 
slide, we are less likely to experience "leaping" sections, and we 
can get 70-100 sections on one slide in very short order!

We also use Tissue Freezing Medium (made by TBS, available from 
Fisher Scientific) to adhere our agar block to the chuck, and find 
that this curls less, and appears to have less static problems than 

Karen in Oregon

>  Has anyone encountered a phenomenon that I occasionally get
>with cryostat frozen sectioning. I assume it is due to static
>electrical charges? the sections tend to "leap" from the knife edge
>onto the slide, the slide may be some several centimeters from the
>section/knife holder.
>There is no logic or consistency to this, irrespective of tissue,
>fixation, temperature, type of slide; but if it is going to happen then
>you can be sure it is when cutting a tiny piece of tissue where
>every section is required! It will often disappear as suddenly as it
>started, sometimes quite impressive when a section fly's several
>cms. to the slide and occasionally lands flat and crease free!
>Any idea's?Oh, and I don't wear nylons (not in work anyway).
>Terry Hacker,
>Medical Research Council,
>Oxfordshire, OX11 ORD
>01235 834393 x360

<< Previous Message | Next Message >>