[Histonet] Question on calcified samples

[Monfils, Paul]

Hello Adrienne,

When dealing with vertebrate tissues, it is possible to cut usable frozen
sections of lightly to moderately calcified tissue such as cancellous bone.
But it is very difficult to cut frozen sections of heavily calcified
materials like cortical bone, without decalcifying it first.  It usually
requires special equiment that is not available too many places, like a
heavy duty freezing sledge microtome. Frozen sections and paraffin sections
of hard bone can be made by decalcifying the bone first (so that it isn't
hard anymore). Unfortunately, with coral you don't have that option. Bone
has a fibrous/cellular matrix that is infiltrated with calcium salts, so you
can remove the calcium salts and still have the basic structure of the
tissue.  But the coral skeleton is virtually 100% calcium salts, with no
organic matrix, so decalcifying it would mean completely dissolving it. The
coral polyps of course would be no problem. They should section easily. 

There is a method by which thin sections of such hard, calcareous materials
can be produced, but it is quite difficult, expensive, and requires
additional special equipment. Briefly, it involves embedding the material in
a hard plastic like methyl methacrylate, cutting a thin slab off the block
with a motorized diamond saw, cementing the slab to a slide, and then
grinding the slab down to the desired thickness with a special motorized
grinding wheel and special abrasives.

> ----------
> From: 	histonet-bounces <@t> lists.utsouthwestern.edu on behalf of
> Adrienne Anderson
> Sent: 	Wednesday, November 22, 2006 11:14 AM
> To: 	histonet <@t> lists.utsouthwestern.edu
> Subject: 	[Histonet] Question on calcified samples
> 
> Hello all,
>   I am a histotechnology student, and my classmates and I will be working
> with some coral samples this year. I was just wondering if there was a way
> to prepare frozen sections on calcified samples, and if so, what equipment
> is needed? 
>    
>   Thank you,
>    
>   Adrienne Mazzante
>   Histotechnology Program
>   Medical University of South Carolina
> 
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