What is the benefit of floating out sections on a slide versus rolling them with plastic and clamping them (besides being quicker)?  I tried floating out PMMA sections and found they wrinkled much more than flattening them with a roller. I didn't try the technique of using a hot plate.  In the technique below, the slides do not lay flat on the hot plate but are propped up so the water drains out from beneath the section?  And, is it ok to dry cut PMMA blocks?  

Signed,

Teri Johnson (The PMMA novice)

Teri Johnson
Managing Director Histology Facility
Stowers Institute for Medical Research
1000 E. 50th St.
Kansas City, Missouri  64110
tjj@stowers-institute.org




-----Original Message-----
From: Karen Pawlowski [mailto:kpawlow@swbell.net]
Sent: Wednesday, February 12, 2003 9:00 AM
To: Sarah Jones
Cc: histonet@pathology.swmed.edu
Subject: Re: attaching MMA thin sections to slides


Sarah,

We have good luck with 0.5 to 6 micron thin sections using the following
protocol:

1) section the 4-6 micron sections dry with a glass knife; or thinner 
sections with a glass knife equipped with a boat filled with distilled
water
2) use a forceps for the dry-cut sections or a tapered wooden pick for
the wet-cut sections to place them on a dome of distilled water on the 
Superfrost Plus slide
3) heat on a hot plate that is set a little less hot that that which 
would make the water on the slide boil (too hot to touch). Place an 
old glass knife on the hot plate so that the slide can be propped up 
on it at the frosted (handling) end. 
4) let the water under the section evaporate and then wait 20 seconds 
before removing the slide from the hot plate and staining
5) stain with filtered toluidine blue, by placing drops of stain so
they dome over the sections and placing the slide flat on the hot plate 
for 15-20 seconds. Don't let the stain boil or dry out.
6) tap off the stain and quick rinse in 3 changes of distilled water,
one change in 70% ethanol and then one more change of distilled water
and place the section back on the hot plate at an angle, over the old
glass knife until dry
7) coverslip

We have had very good luck with this protocol, in fact we have none of
the sections releasing even if we have to remove the coverslip and 
restain.

Good luck,

Karen Pawlowski, Ph.D.
Research Scientist
University of Texas at Dallas
Dallas, Texas