[Histonet] Bone processing

[Gayle Callis]

Steven,

Those protocols are from people who did their animal tissues in a certain 
way, and not everyone does it just exactly like the protocol submitted for 
the Animal Processing Manual - the protocols are not written in stone, but 
are good guidelines for successful animal tissue work.

As for our mouse bone work, we use a Sakura Finetek VIP, and extend 
processing for mouse joints (denser due to the collagen matrix of 
decalcified bone).  We do ambient i.e RT temperatures for dehydration and 
clearing and use vacuum and pressure throughout.  Adding temperatures to 
alcohols, clearing agents sometimes adds to hardness of tissue at 
sectioning - animal tissues, in particular the tiny mouse soft tissues.  In 
general, animal tissues are much leaner, less fatty than human tissue  and 
overdehydration tends to dry out rodent tissue more.  This species is not 
the only one that suffers from lean i.e birds, reptiles, rabbit, and many 
others.  We  tend to do custom processing for rodent work,  and have 
special schedules for mouse brain versus hamster brain versus rat brain 
versus lung and other soft tissues.   Larger animals processing can be more 
like human tissue processing i.e. cow, horse, dog, cat, but sometimes these 
can be dry also.

What you want to do is remove the free water from the tissue spaces and not 
the bound water found on the proteins (that is what makes mouse spleen hard 
little nuggets sometimes referred to as overprocessing).  If your tissue 
seem dry at sectioning - you can soak a faced block on ice with water on 
top and reevaluate if you need to cut down on total time of processing, in 
small increments of time however.

Good luck

At 02:19 PM 7/28/2005, you wrote:
>New to research, just received the "Animal Processing Manual".  I'm about 
>to process mouse joints and I noticed a much longer time especially in the 
>infiltration paraffins.
>
>Along these lines I also noticed processing for mouse/rat tissue calls for 
>only RT processing and no vacuum/pressure..
>
>I have a clinical background so some or allot of this is a "tad" 
>new.  Anyone up to explaining the big picture difference between human 
>tissue verses animal tissue processing.
>
>Steve
>
>
>
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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)