Re: spurr

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From:"R.Wadley" <>
Date:Thu, 18 Mar 1999 08:50:12 +1000
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	I think you may have some problems here.  I can understand the use of
Spurr's resin, it does have a very low viscosity, I prefer Epon 812, it is
slightly less toxic to the operator & I'll trade that off with a slight
increase in viscosity any day.

	However, just how big is a "large block"?  Spurr's, & in fact most epoxy
resins tend to be rather brittle, this is OK for EM work where a maximal
section size may be maximally ~3 mm per side.  Epoxy resins can be cut
using either solid or disposable microtome blades, but you are going to get
a lot of chattering & shattered sections.

	Your best hope is to cut sections with a hand or powered saw about 1 - 2
mm in thickness, & use a polishing technique as in lapidary (possibly also
dentistry).  So grind & polish the face of the block so that the specimen
is exposed, cut off a thin slice.  Bond the polished face to a slide (If
this is done before cutting it may prevent cracking of the slice), & then
grind & polish the rough side down to an appropriate thickness.

	Please not this is a hazardous operation, resin dust is just as toxic as
the unpolymerised components, & possible more hazardous if you consider the
effects the dust on the lung.

	Hope this is more helpful than depressing.


	Rob W.

At 10:09 AM 3/17/99 -0500, you wrote:
>I am going to be cutting some large blocks of undecalcified 
>bone containing an implant.  The specimens are embedded in 
>Spurr resin because the methacrylates will dissolve the 
>implant.  Does anyone have any experience with this type of 
>thing?  I can only find references for using Spurr for EM work 
>and cutting them on an ultramicrotome.  I will be using a 
>Polycut E to cut the blocks.  Thanks in advance for any 

R. Wadley, B.App.Sc, M.L.S
Laboratory Manager
Cellular Analysis Facility
School of Microbiology & Immunology
UNSW, New South Wales, Australia, 2052
Ph (BH) 	+61 (2) 9385 3517
Ph (AH)	+61 (2) 9555 1239
Fax 	+61 (2) 9385 1591
	(Under development)

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