Hi Joe,
  It may be that your specimen is too large.  I could be wrong on this.  But usually with plastics, the smaller the better.  Try a piece that will fit into a JB-4 mold and see if that polymerizes ok.  I'm sure some of the plastic experts like Gail will have a good reply.
  -Sarah
PS to Cliff who said "your poll in (is?) completely skewed so the results are meaningless.  Reminds me of some recent presidential elections.  Jeesh, I hope my opinion isn't meaningless...  I was told just this week that it's ok to be a histotech.  ;)


Sarah Jones HT(ASCP)
Dept. of Vet. Anatomy & Public Health
Histology Lab
Texas A&M University
College Station, TX 77843-4458
phone: 979-845-3177
fax:  979-458-3499


>>> Joe Moore  06/27/03 01:24PM >>>
Hello everyone,
	We have been experiencing problems trying to use immuno-bed kit from 
Polysciences.  The tissue is a half section of a rat testis about 1 inch by 
1/2 inch.  The protocol we have been using is as follows:

Perfusion fixation with 4% paraformaldehyde in 0.05M PBS (pH 7.4) followed 
by dehydration in 50, 70, 95, 100x2 EtoH.  Infiltration was done with an 
"infiltration" solution contained in the kit.  Blocks were then polymerized 
under vacuum at 4 degrees.

The tissue center shows incomplete polymerization even though we extended 
the polymerization times up to twice the maximum recommended and the resin 
itself is brittle.  Polymerization of blank blocks at room temperature 
worked fine and were easily sectioned.  Does anyone have any experiences 
using the immuno-bed and can shed some light on this problem?