How big are the pieces?   It would be advisable to have longer processing 
schedule, rather than a routine schedule.  This sounds like poor dehydration 
and poor paraffin infiltration.  Also, if your samples are less than 3 mm 
thick, then you get the potato chip syndrome, where the bone is NOT 
supported well enough, plus trimming should be done in very thin increments 
(setting) with a SHARP  blade.  High profile blades work much better with 
harder bone but if the bone is perfectly and totally fixed before 
decalcification, tested, and processed properly, thin profile will work 
although not as nicely.

You should do a decalcification endpoint test and there is a simple one that 
works quite nicely, a weight gain/weight loss.

If the bone appears chalky or opaque, then the bone is either poorly 
decalcified, poorly processed or both.

Longer infiltration in a harder paraffin i.e. Tissue Prep 2 ThermoScientific 
ala Fisher is excellent for bone and three changes minimum.

The horse bone may be harder, depending on age of the animal, as compared to 
another species.

Soaking only works IF the bone is well decalcified and processed.  To avoid 
surface decalcification, endpoint test.   I will be happy to send the 
protocol for that, but you need a balance that weighs in milligrams.

Gayle M. Callis
HTL/HT/MT(ASCP)


----- Original Message ----- 
From: 
To: 
Sent: Tuesday, August 05, 2008 6:07 PM
Subject: [Histonet] Horse bones


> We are trying to section pieces of horse femurs, fetlock and carpal 
> joints.
> They have been decalcified with either HCl decal or formic acid  decal.
> Before routine processing the bones appear to be decalcified, but  at 
> sectioning
> they are very hard and brittle (even after surface decal) and chip  out of 
> the
> paraffin block.
> Any suggestions would be helpful.  A pathologist suggested a soap  soaking
> solution but could not remember the name of the soap.
>
> Help and thank you,
>
> R. Berger, HT
>
>
>
>
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