Re: Wavy sections -Reply
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From: | Sarah Christo <schristo@CVM.TAMU.EDU> (by way of histonet) |
To: | histonet <histonet@magicnet.net> |
Reply-To: | |
Content-Type: | text/plain; charset="us-ascii" |
Dear Marilyn,
If chatter is not your problem, I have seen this
happen when sections come loose from the slides
during staining.
Sarah, Texas A&M
On Mon, 14 Dec 1998, Marilyn Woods wrote:
> Looking for suggestions on the cause of wavy sections, so bad that we are
> unable to focus under high power. This has happen out of the blue without
> changing any procedures. I am cutting all skin, some look good, but this
> problem seems to affect the staining ex. muddy appearing, poor contrast and
> understaining. All temps. are with norm. except of a paraffin bath on
> processor is 64 C. Sections have been good 2 days a week then progressively
> get worse.
Your use of the word "wavy" suggests that the thickness varies,
in stripes or bands parallel to the knife edge, or that wrinkles
were not flattened out. The former is more likely because you
would have seen failure to get rid of wrinkles. The artifact of
thickness varying as the knife cuts through the block is called
"chatter." Perhaps this is what you have. It is attributed to
vibration of either the knife edge or the specimen, and the
remedy is to tighten everything up on the microtome, including
the little screws that hold a disposable blade onto its support
(if applicable to your equipment).
For an excellent account of chatter and many other cutting artifacts,
see "An Introduction to Histotechnology" by Geoffrey Brown (Appleton
Century Crofts, New York, 1978. ISBN 0-8385-4340-5). I don't know
if it's still in print. I found my copy quite recently, by chance,
in a second-hand bookshop, having been previously unaware of it.
This nice hard-cover volume may not have got enough publicity. The
practical instructions and hints about details are first rate. The
author evidently draws on experience in the U.K. and U.S.A.
This may not answer your question fully, because even uneven sections
and those with chatter can be brought into focus if the microscope
knob is continually adjusted while moving across the field. Maybe
more than one factor is involved, but something wrong in the cutting
is probable on the strength of what you say.
John A. Kiernan,
Department of Anatomy & Cell Biology,
The University of Western Ontario,
LONDON, Canada N6A 5C1
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