[sci.bio] plastic sections - problem

paleo@ecsvax.UUCP (Constantine A. LaPasha) (07/13/89)

We have a problem with some parts of our protocol for
preparing permanent slides (microscope slides) of sections
of plastic embedded plant material.

We are embedding samples of wood (secondary xylem) in
hydroxy-propyl-methacrylate catalized with benzoyl peroxide
and mixed with triethylene glycol as a plasticizer.  Blocks
are polymerized at 50-60C for 24-48 hrs and sectioned at
5-10 microns on a rotary microtome with steel knives.  Sections
are floated on water and dried on glass slides.

Cover glasses are mounted with "Plastic Mount" from Polysciences
and cured under long wave UV for ~2 min.

Now the problem -- blank areas of plastic in sections prepared
as above develop what appears to be crazing - small dark lines -
that are quite apparent when viewed with phase contrast.

My guess is that there is some incompatability between the 
embedding plastic and the mounting plastic.  I don't remember
this problem when I used to use canada balsam or permount or
kleermount in xylene to mount cover glasses.

Has anyone else had this problem?  Any suggestions for remedies?

Thanks.

Kostya LaPasha

paleo@ecsvax.uncecs.edu

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Kostya LaPasha        paleo@uncecs.edu   or   paleo@ecsvax.uncecs.edu
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