I used this technique on blocks of titanium-coated epoxy implants and the
tissue, including newly-formed bone, in which they were implanted. The
blocks were about half a centimetre square, which meant much-extended
infiltration times. I used glass knives to cut sections 1-2 mu thick for LM
and a diamond knife for thin sections of a much smaller ROI, and it was
quite successful. If you need to see the actual hydroxyapatite crystals,
then obviously this method is pointless. But if you need to see the
structures attached to the hydoxyapatite undistorted, and are not interested
in the implant itself, then embedding before decalcification allows this.

Lesley Weston.


on 06/09/2002 10:40 AM, Gayle Callis at gcallis@montana.edu wrote:

> This would be a possiblity with PMMA. However, small undecalcified bone and
> hydroxyapatite implant materials can be sectioned directly after embedding
> in PMMA, a good strong microtome and a d profile tungsten carbide blade.
> How big a sample are you talking about in EPON and do you use glass or
> diamond knives? Most EM size samples are really tiny.  Enlighten us on
> size, please!  
> 
> If you need to see calcification of hydroxyapatite and the interface of
> cells with this calcified material, surface decalcification may defeat the
> purpose as would any other decalcifying method.
> 
> 
> 
> At 09:03 AM 9/6/02 -0700, you wrote:
>> You might be able to compromise on decalcification. Embed in Epon or one of
>> the substitutes. Trim and thick section your block to the ROI and then place
>> the cut face of the block in EDTA for a few hours. Rinse in water and
>> section immediately. This leaves the area where the hydroxapatite was
>> undistorted, while still allowing good sections. Hope this helps.
>> 
>> Lesley Weston.
>> 
>> 
>> 
>> on 05/09/2002 8:43 AM, Patsy Ruegg at pruegg@colobio.com wrote:
>> 
>>> no way in my experience.  you might need to embedd in GMA or MMA if you
> don't
>>> want to demineralize.
>>> patsy
>>> 
>>> Kathleen Cormier wrote:
>>> 
>>>> Hello all,
>>>> 
>>>> I have a researcher who is submitting hydroxyapatite and cells as FFPE. Is
>>>> it possible to get acceptable sections from hydroxyapatite that are FFPE
>>>> and not decalcified? All I get is shredding. The researcher is afraid that
>>>> decalcification would compromise the integrity of the construct. Any
>>>> suggestions or references would be greatly appreciated!
>>>> 
>>>> Thanks!
>>>> 
>>>> Kathy Cormier
>>>> Histology Supervisor
>>>> Division of Comparative Medicine
>>>> MIT
>>> 
>>> 
>> 
>> 
>> 
>> 
>