I never cryopreserve rodent tissues before snap freezing unless they are
prefixed in PFA or NBF before freezing.  Just lower the temp on cryostat to
-16C and go for it.  You can try different fixatives, PFA, NBF,  acetone 10
min on air dried sections 30 min to overnight), RT alcohol 5 min fix on air
dried sections or acetone/alcohol RT fix 5 min on air dried.

Do not defrost the tissue, cut the frozens on blocks as they are, put
tissue on block with OCT, can even surround tissue with OCT then let it
freeze.



08:11 AM 8/31/00 -0600, you wrote:
>Greetings everyone!
>
>I just got a call from the guy I do HBV IHC for and he has a project for
>me.  Th problem is that all his tissues (transgenic mouse livers) are
>frozen, the tech who froze them put them in lq N2 but DID NOT use a
>cryopreservant.  We want to do frozen sections on these and perform HBV
>IHC on them.  Is it best to defrost them and fix in BNF or leave them
>frozen?  The concern here is all the other work I've done has been on
>BNF fixed & paraffin embedded tissues and we would like some modicum of
>consistency.
>
>thanks
>
>Connie McManus
>
>
>
>
>
Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303