We usually end up walking a fine line between wrinkles and exploding blocks.
Turn the temp. up as high as you can get away with.

Try drying your sections at 37C or RT overnight. This helps the wrinkles to
flatten.  Avoiding coated slides helps this process - but everything floats
off during staining.

Warm the block before cutting thick sections.

Place a glass slide big enough to hold a short ribbon of sections on the
edge of your waterbath.  Flood with 20% alcohol and place the ribbon onto
it. If there are air bubbles trapped underneath they can be gently displaced
with forceps. Carefully tip the alcohol off into a container then float out
the ribbon on the water bath.

Cut sections as thin as you can get away with.

Blame the fixation/processing if done by someone else.

Look for a suitable spell in a Harry Potter book.

You're not alone!

Andy Shand


----- Original Message -----
From: Andrea Grantham <algranth@u.arizona.edu>
To: <histonet@pathology.swmed.edu>
Sent: Thursday, October 19, 2000 5:25 PM
Subject: wrinkled brains - HELP!


> I've been trying to get decent 10 micron sections of rat brains and the
> cutting is great but the brain tissue puckers when it hits the waterbath
> and I can't get a flat section on the slide.
> The brain was perfused (not by me so this is a guess) with
> paraformaldehyde, stored in 0.1M phosphate/4% paraformaldehyde before it
> was brought to the lab.
> I processed it on my little old rotary processor - one hour for each
> station beginning with 70% ETOH. I allowed extra time for infiltration
> since it was a thicker piece of tissue. I use paraplast xtra. This is the
> paraffin that I use routinely in the lab for all types of tissue.
> Waterbath temp is 42 degrees. I use DI water and I even tried putting in a
> small amount of alcohol in the waterbath.
> Any suggestions for flat sections? Should I raise the temp in the
waterbath
> - I don't want the tissue to expand so fast that it "blows up".
> At this point can the brains be re-infiltrated with a different type of
> paraffin? I'm thinking of a softer type.
> Thanks!
> Andi
> .....................................................................
> : Andrea Grantham, HT(ASCP)     Dept. of Cell Biology & Anatomy     :
> : Sr. Research Specialist       University of Arizona               :
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> : (voice:  520-626-4415)        Tucson, AZ  85724-5044    USA       :
> : (FAX:  520-626-2097)          (email:  algranth@u.arizona.edu)       :
> :...................................................................:
>            http://www.cba.arizona.edu/histology-lab.html
>
>