Sue,  I have used Araldite 502 with great results for histochemistry,
immunocytochemistry including immunofluorescence.
I have routinely sectioned down to 0.5 microns and less and achieved beautiful
staining. Section with a glass or an old diamond knife. treat slides with
sections in 1:1 sodium ethoxide:toluene from 1 to 3 minutes, the latter for 2u
sections followed by 100% toluene then dehydrate and stain. Obviously, the
thinner the sections the longer the incubations due to reduced antigens. For
histochemistry heating the solutions expedite staining at reduced times.


Hank Adams
Manager, Microscopy Core
Molecular Genetics
MD Anderson Cancer Center
Houston, TX