[Histonet] digesting soft tissue

[Gayle Callis]

This is actually a published method in J of Anatomy to produce museum
specimens for teaching sometime in early 80's??? 

Buy BIZ laundry detergent (or raid the family laundry supply!) make a 20%
solution, heat to 80C, less than boiling.  Suspend bones in this hot
solution (or suspend and bring solution to working temperature, don't
boil!)using cheesecloth to retain small boney parts that can fall off and
handle a slippery, hot specimen easily. BIZ enzyme detergent loosens soft
tissue to the point you can push it off with gloved fingers.  It will take
cartilage off but that was acceptable.  Wear a mask when weighing - BIZ
dust is very irritating to nasal passages and also skin. Digestion takes
several hours if bone is large, so test frequently to see if soft tissue is
releasing.  

I have done formalin fixed bone, rinsed over night in running tap water to
remove the formalin (NBF kills the enzyme!), then BIZ.  NBF fixed bone
stablilizes the soft tissue attachments to make them more resistant to
enzyme. Wear gloves, safety glasses and rinse off detergent before handling
bone excessively, slippery, and irritates skin.  Push soft tissue off, use
old tooth brush and a dull knife to do gentle scraping if needed. When
finished, rinse bone well, then air dry.  The result is a BLEACHED, clean
bone that doesn't smell bad - particularly when the digestion process is
happening.  Fixed is less smelly, unfixed means you are cooking bone while
enzyme works - not so pleasant - use a hood.  

Have done whole bovine calf heads, bovine vertebral columns, bones from
hind and forelimbs;  rat and mouse heads, rat femurs/tibias.  Beware - the
enzyme will digest any soft attachments IF you let bones digest too long.
Bones will fall apart, then you have to be a good anatomist and glue
(thicker superglue works) tiny parts back in their relative,
interdigitating, tight positions - a tedious but educational procedure on
how our boney parts go together. 


 
Gayle Callis
MT,HT,HTL(ASCP)
Research Histopathology Supervisor
Veterinary Molecular Biology 
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367 (lab with voice mail)
406 994-4303 (FAX)