Dear Gary,
   It would make things much easier to use cassettes.  I sometimes process by hand at the paraffin stage and I don't have a problem with the paraffin solidifiying.  I think it must happen to you because your volume of paraffin is so low.  Are you using the small vials at the paraffin stage too?  I use a pan about 4" x 8" x 3" deep and even with the door open for several minutes the paraffin stays melted.  This is even with a low temperature at 59 degrees.  If the cassettes are allowed to drain between tranfers, there shouldn't be a problem with wax dripping.  Paper towels placed under the cassettes during transfer would also work.  

Sarah Christo, HT (ASCP)
Texas A&M University
College of Veterinary Medicine
Dept. of Vet. Anatomy & Public Health
College Station, TX  77868-4458
schristo@cvm.tamu.edu

>>> Gary Radice <gradice@richmond.edu> 09/09 1:44 PM >>>
Histonetters,

I teach an undergraduate microanatomy class in which the students learn to
make their own preparations of mouse and frog tissues. Because we are not a
production lab we don't have automatic processors. At the moment we don't
use tissue cassettes, either. Rather, I have folks carry their specimens
through the infiltration steps in individual snap cap bottles. This works
OK if one or two people are working but not when all 15-20 students are
working. The main bottleneck is the paraffin oven. Every time someone opens
the door, everyone's specimens congeal.

I'm looking for suggestions to work around this problem. One idea is to
switch to cassettes that can be dunked into larger volumes of wax, which
would be less subject to temperature swings. But then how would I avoid wax
dripped all over the inside of the oven as folks transfer their tissues?

Any suggestions for how to scale up?

Gary Radice		804-289-8107
Department of Biology	804-289-8233 (FAX)
University of Richmond 	gradice@richmond.edu 
Richmond VA 23173