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?