One scan of a museum collection will prove (as Dr. Gibson of the NHM has
stated) that synthetic media do not stand the test of time. You can
restore some specimens with the method Derek describes below, but if the
crystalization has gone too far the specimen will also fracture. Then you
end up trying to remount bits!
I get better results sometimes by adding xylene at the edge to soften the
medium, then later (depends on the thickness of the preparation and other
factors, maybe age of the prep.) freezing the mount, and flipping off the
cover slip while very cold. Most of the time (95 of 100?) the specimen and
mountant will remain on the slide while the cover slip comes off clean.
Then remove the mountant only in the perimeter of the preparation by
scoring around the animal and chipping off the excess. Cover and surround
the animal with thin balsam and put on a new cover slip. Skip Sterner
and Mary Hansen Pritchard taught me most of this method.
Now if someone could tell me how to restore protist Type slides in Hoyer's
Judith C. Price
Canadian Museum of Nature
jprice at mus-nature.ca
"derek a. zelmer" (zelmeda4 at WFU.EDU) writes:
> On Tue, 22 Oct 1996, Riccardo A. Fiorillo wrote:
>>> Thank you for your quick response. I am familiar with Canada Balsam, but
>> it is out of my price range. Have you heard anything about Cytoseal? I
>> saw it in the Carolina Math and Science Catalog #66, and I was wondering
>> if it is worth trying. Thanks again, Ricky A. Fiorillo.
>> I am not familiar with it at all. If you have to use a synthetic medium,
> you may be able to rescue your specimen if the medium crystalizes over
> time, by floating off the coverslip with xylene, and remounting the
> specimen.. I will be doing a lot of that this year for teaching slides
> that have outlived their mountant. For valuable specimens, the risk of
> damage is too great. The best advice I can offer is to teach a
> parasitology lab, and leave some room in the course budget for Balsam...
>> Derek Zelmer