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

[Judith Price]

We sometimes found similar white precipitate in Crustacea samples at the Canadian Museum of Nature. The nice guys in our Mineralogy group ran it through their spectrometer and determined it was cholesterol. Presumably these fats were dissolved from the animals and then precipitated, perhaps due to a change in preservative chemical(s).

Judith Price
(retired but still reading!)

> On Nov 27, 2018, at 2:09 PM, Tocci (Lewis-Gentry), Genevieve E. <glewis-g at oeb.harvard.edu> wrote:
> 
> Hi Alex,
>  
> I can’t say what it is, but it is very unlikely to be fungi. The ethanol should kill any fungal growth and is what we use to preserve our fluid collections as well as treat any moldy things. You can always look under a microscope to be sure.
>  
> Best,
> Genevieve
>  
> =================================================
> Genevieve E. Tocci
> Senior Curatorial Technician
> Harvard University Herbaria
> 22 Divinity Ave., Cambridge, MA 02138  U.S.A.
> Phone: 617-495-1057  Fax: 617-495-9484
> glewis-g at oeb.harvard.edu
>  
> From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> On Behalf Of Alex Krohn
> Sent: Tuesday, November 27, 2018 1:53 PM
> To: nhcoll-l at mailman.yale.edu
> Subject: [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/
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