Another Re: [Histonet] Bone decalcification
Acid decalcification BEFORE fixation will macerate your tissues aka protein
hydrolysis. It will destroy both soft tissue morphology and nuclear
staining, and there is no way you can repair this kind of chemical
destruction of tissues.
Total fixation is needed to protect the tissues from the effects of acid
IF the bone is small, i.e. a bone biopsy or cut down into a very small
piece, then a formic acid/formalin (combination fixation and
decalcification) can be used successfully. This is NOT recommended for
really large bones (mfrs even make these recommendations in their
instruction sheets). One message kindly provided vendor recommendation
for this fix/decal solution.
If you do not want to use formic acid/formalin, then fix the bone first in
NBF and proceed to a acid decalcifier. Keep in mind, strong acids i.e. HCl
(commercial solutions work very well) can damage antigens if bone is left
in these solutions too long. For a gentler acid decalcifier, buffered
formic acid is available commericially.
The recommendation about a textbook is a good one - several devote whole
chapters to bone histotechnics, including how to decalcify, etc and what
will happen IF you do not perform these procedures carefully.
Our personal preference is to totally fix the bone in NBF. To speed up
both fixation and decalcification, reduce the size of the bone i.e. cut a
representative sample for fixation followed by decalcification. This also
helps with the combo fix/decal method. If you suspend the bone, the
reagents surround all sides of the bones.
The only time I have seen unfixed bone followed by decalcification is with
EDTA, and it was a tedious, long drawn out method, used for research
projects and NOT the clinical setting where you need a diagnosis asap. The
EDTA methods are found in several publicaitons.
At 04:40 AM 4/24/2006, you wrote:
> I just wanted to know other histo techs opinions on bone decalcification.
>I learned in school that you decal the bone than you fix it. I have a
>pathologist who claims she learned it the hard way, and that it is better to
>fix the bone than decal it. What did you learn on how to do this procedure?
>This pathologist claims that fixing prior to decaling keeps the cells more
>intact. Any opinion on your procedure or your technique is appreciated.
>Heather A. Harper
>Histonet mailing list
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-4303 (FAX)
Histonet mailing list
<< Previous Message | Next Message >>