[Nhcoll-l] Precipitate or Mold in Ethanol Stored Specimens

[Fabian Neisskenwirth]

Dear Alex,

 

I had the same issue here while restoring an old fish collection. This is due bad transfer into Alcohol.

 

If the Formalin fixed specimen is not transferred properly (at stages of at least 20%) in to EtOH, this crystal’s will appear (supposed to be called para-formaldehyde). 

 

The solution is simple: wash the specimen with a fine toothbrush (use clean Alcohol to wash), filter the conservation liquid from the crystals and put the clean specimen back.

 

Next time be sure to transfer the specimen right (the shrinking will be less extreme on the specimen too)

 

 

Hope this helps.

 

 





--
Fabian Neisskenwirth
Präparation
Naturwissenschaftlicher Präparator

+41 (0)31 350 72 25

 <http://www.nmbe.ch/> NATURHISTORISCHES MUSEUM BERN
Bernastrasse 15, CH – 3005 Bern
www.nmbe.ch

 <https://www.bgbern.ch/> Eine Institution der Burgergemeinde Bern

 

 

 

 

 

Von: Nhcoll-l [mailto:nhcoll-l-bounces at mailman.yale.edu] Im Auftrag von Alex Krohn
Gesendet: Dienstag, 27. November 2018 19:53
An: nhcoll-l at mailman.yale.edu
Betreff: [Nhcoll-l] Precipitate or Mold in Ethanol Stored Specimens

 

Hi everyone,

 

I recently found some bizzare white granules in some our ethanol preserved specimens. See the attached photos. The white granules tend to stick to the items in the jar, rather than rest at the bottom of the jar. They do not crush easily (like I imagine precipitates would), but instead squish more like tiny styrofoam bits or pieces (like I imagine mold would).

 

Has anyone seen this before? I washed the specimens and jars in fresh 70% EtOH, and then replaced the EtOH in the jar. So far no new granules have appeared. If anyone has any better ideas of what this might be or how to treat it, I'm very interested.

 

Thank you!

 

Alex Krohn

 

---------------------

Assistant Director

Kenneth S. Norris Center for Natural History

University of California, Santa Cruz

 

https://norriscenter.ucsc.edu/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.yale.edu/pipermail/nhcoll-l/attachments/20181128/202fe030/attachment.html>