Hi everyone

Yet more dialogue re this subject. Once again, I feel I must add my two
pennies/cents worth. We are committed rollers in talc, and freeze
directly by immersion in liquid N2. However, we used to freeze the block
only, and allowed it to come "up" to cutting temperature by storing in
the cryostat for 15 to 30 minutes. Only then, did we try to orient the
block on the cryostat chuck, by using OCT and freon. My experience is
that best results are obtained by freezing only what you want frozen, ie
muscle. It seems that Jonh Keirnan will see the fruits of this method
fairly soon, and I can include some histochem as well if he wishes as
proof. BTW we were able to freeze blocks up to 5 or 6 mm diameter with
this method.

One last thing, which has just been found out. If ice crystal artefact
is apparent in the block after freezing, it can often be reduced or even
remedied by allowing the tissue piece to thaw FULLY and by re freeezing
properly.

Happy histochemistry everyone.

Regards
-- 
Hedley David Glencross