Re: bone implant

From:Gayle Callis <>

Tungsten carbide knives, Delaware Diamond Knives, will cost around $1200
for a D profile, then there is a reconditioning fee, when it is dull and
dinged up, at $200 a pop. Pricey at best, but decalcified bone CAN be cut
with these knives on a good microtome, a way of handling nasty, difficult

Some of the first work on methylmethacrylate embedded bone was done by Webb
Jee, at University of Utah, on decalcified bone (EDTA decal'd) embedded in
MMA.  Tedious, and not much fun, been there, done that!  IF you try MMA
with acid decalcified bone, you will have to rinse the begollys out of it,
to remove all traces of acid.  This messes up plastic polymerization EVEN
if you tried GMA, done that too!   

1.5 X 1.5 inches is too large for a glass knife, plus GMA will not work as
well as MMA for such a huge specimen, polymerization will be very difficult
to control on such a large block, plus even getting good infiltration of
this plastic. Whoever told him a diamond blade would work is probably not
aware these are TINY blades (for his monster specimen?!?) and really

There is a possibility for you, to do extended processing into paraffin,
you are looking at approx 1 1/2 to 2 hour PER station, even in paraffin,
minimum of 3 changes, using vacuum/pressure.  If you use Tissue Prep 2
(Fisher) you will have a harder paraffin, better for what you are doing.
Cut with a tungsten carbide knife, or try a high profile disposable blade,
low may be a tidge less stable, being thinner and less blade mass.  Do a
STerchi Tape transfer with some packaging tape, you will find her article
in J of Histotechnology, in late 80's ofr 90's (could find it for you!).
The tape that works best is a 3M tape, # 3750, buy at office supply stores,
clamp section on tape onto a gelatin subbed slide, clamp tightly and put in
60C oven overnight, go through 3 - 4 changes of xylene, the section stays
on slide, and tape is soaked off, extra changes take care of tape goo.

As for your researcher, he needs to look into how to do things BEFORE he
starts, it wouldn't hurt him to learn a few things about different bone
technics in order to know what the heck he is even doing in the first
place. DUH!  Putting the cart before the horse here!!  My sympathies. I
think he should do the sectioning, might learn a thing or two along the
way, just one of my funky comment days, sorry!

If you need anymore help on this, I will be glad to discuss it, have done
the tape tranfer, even on paraffin embedded eyes (large) with excellent
results, the knife you use may be more of a limiting factor, but the high
profile (like Accuedge, TBS coated high profile) could work.  It takes a
bit of practice, but only a few minutes of that.   

At 09:35 AM 10/25/00 -0500, you wrote:
>I've got a couple of questions for you "Hard Tissue" folks.
>A researcher has asked me to paraffin embed a decalcified bone with a 
>Tantalum implant.  His words, "It's just a sponge!  It cut on the band saw 
>pretty well!"   HAH!  HAH!  HAH!  I told him that I had news for him.  This 
>is NOT going to cut on a paraffin embedded block.  Well, he wants to know 
>how to do it.  I suggested he look into several different things.  Well, he 
>comes back and wants ME to do the looking.  Anyway,  Is this something that 
>is even cutable (ie with titanium blade or something) ?  He said maybe he 
>needs a diamond blade.  Now, I may be wrong, but this specimen is from a 
>dog and is about 1.5 inches X 1.5 inches.  I didn't think that a diamond 
>blade would work.  Someone told him it would.  If a titanium blade is a 
>possibility, where do you purchase these and how much are they 
>approximately.  Maybe the price tag will scare him off.  Then there's 
>always grinding the specimen after plastic embedding.  Is this something 
>that might be a possibility with this type of implant?
>	This should be a start and then I'm sure I'll have more questions.  Thanks!
Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303

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