Joe - Our EM lab uses the Immuno Bed kit from EM Sciences.  I think it is the same vendor.  If you don't get any answers here, contact them at:

donna.craft@ht.msu.edu or ralph.common@ht.msu.edu

I am sure they could help you out.

Joe Moore <jmoore@bucknell.edu> wrote:

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?