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

[Rittman, Barry R]

It is a long time since I polished ground sections (usually without the
benefits of a Buehler polishing machine), and I totally agree with
Gayle's comments.  
Another point worth mentioning perhaps is that several of the diamond
pastes are colored to prevent mixing up grades I assume. This dye plus
the oil base tends to stain some substances in the slices whether they
are unembedded or in plastic. The same is also true for polishing rocks
slices.
Barry

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Gayle
Callis
Sent: Tuesday, August 16, 2005 12:16 PM
To: RCHIOVETTI <@t> aol.com; Histonet <@t> lists.utsouthwestern.edu
Subject: [Histonet] removing debris Re: Grinding & polishing of
resinsections.

Sulekha,

  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 <@t> 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?
> >
>
>Sulekha,
>
>Can you completely remove the plastic from the sections before
staining?
>This would certainly remove the bulk of the contaminants, since they're

>getting
>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, 
>with
>no plastic  Wash and rehydrate thoroughly after the "deacrylation," and

>proceed
>with staining.
>
>See the following link:
><
>http://www.ecmjournal.org/journal/supplements/vol007supp01/pdf/vol007su
pp01a82.pdf>.
>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
MT,HT,HTL(ASCP)
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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