[Histonet] removing debris Re: Grinding & polishing of resin sections.

From:Gayle Callis


  am assuming you are doing thick slab type sections with grinding/polished 
and possible surface type staining?

To remove debris from ground sections, immerse sections into water with a 
drop of detergent in a beaker,  ultrasonicate section - you will actually 
see the debris fly off the surface.  Be sure to rinse with distilled water 
or simply hold the section under a hard stream of tap water to rinse off 
residual detergent.    We did this with all our slab MMA bone sections but 
you MUST use water based alumina  polishing compound as a final polish 
instead of diamond paste if the paste contains oil lubricants, not 
good!!  Alumina is also MUCH cheaper.  Oil lubricants are difficult to 
remove unless you use some organic solvent and you may not want to etch the 
resin with a solvent just to clean off debris.

We would grind with 640 grit paper then go directly to 1 um size alumina, 
you can achieve a fine polished surface and remove any unsightly scratches 
which pick up stain.  There is a 0.1 um and 0.3 um size alumina, but we 
rarely used these.  We had a Buehler grinder polisher, started with 320 
grit paper,  went to 640 then 1 um alumina polish compound. Depending on 
what grit size your diamond cut off blade has on it edge, that determines 
the next grit you would go to to start grinding.  So if the blade had 240 
grit diamond embedded in the edge, then you can proceed to the next grit on 
grinding paper to begin final grinding.  If you use too low a grit number 
you can actually grind too much specimen away, ruining a lesion or area you 
want to see.

I would want to remove this fine debris pushed into little spaces (they are 
there!) before removing plastic too, it could continue to float around in 
staining solutions.

It is wise to wash between each grit, so you are not retaining big grit 
before the next paper grit size.

At 10:03 AM 8/16/2005, you wrote:
>In a message dated 8/16/2005 2:00:20 AM US Mountain Standard Time,
>sulekhababy@yahoo.co.uk writes:
> > After grinding &polishing using grinding papers and diamond paste of
> > different sizes we find the sections contain lots of debris.What can I 
> do to clean
> > these resin sections before it is stained?
> >
>Can you completely remove the plastic from the sections before staining?
>This would certainly remove the bulk of the contaminants, since they're 
>embedded in the sections during the polishing process.
>It would be similar to the deparaffinization of paraffin sections.
>You could probably use 2-methoxy ethyl acetate to remove the methacrylate
>plastic.  Then you would simply have the specimens remaining on the slide, 
>no plastic  Wash and rehydrate thoroughly after the "deacrylation," and 
>with staining.
>See the following link:
>Robert (Bob) Chiovetti, Ph.D.
>The Microscope Works
>Arizona's Microscopy Resource
>132 North Elster Drive
>Tucson, AZ 85710-3212 USA
>Tel./Fax 520-546-4986
>Member, Arizona Small Business Association - ASBA

Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367 (lab with voice mail)
406 994-4303 (FAX)

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