[Nhcoll-l] Cleared and stained specimens

[Simon Moore]

Hi Tonya,

Happy New Year to you too! 

Your specimens are most likely stored in glycerine but I often use 70% as my final storage solution, as full strength can some cause indenting, due to a slight implosion, of delicate skulls.  I also add a crystal of menthol as it forms a surface film that prevents any fungal spores from ‘germinating’ so you may notice a smell of some fungal inhibitor. 

 A specific gravity test should give you a rough idea of the concentration, otherwise I use the Schleren Optics test which involves making up a series of concentrations from 50% to pure in 10% steps. By pipetting a drop of a given concentration into a small sample of unknown concentration you can see whether the drop mixes in easily with the mystery solution or forms the wavy mixing lines (Schleren Optics) if less compatible. But there may be a refractometer available that will measure glycerine concentrations more accurately.

You will likely get several other suggestions as to storage media.

With all good wishes, Sumon

Simon Moore MIScT, RSci, FLS, ACR
Conservator of Natural Sciences and Cutlery Historian.

www.natural-history-conservation.com



> On 9 Jan 2024, at 01:41, Haff, Tonya (NCMI, Crace) <Tonya.Haff at csiro.au> wrote:
> 
> Hello all,
> 
> Happy New Year! It's been very quiet here of late, so I am guessing many people are still enjoying their holidays?  For those of you back at work, I have a question regarding cleared and stained specimens.
> 
> We have about 20 or so small frog specimens that have been cleared and stained, and which to me look to be stored in glycerine. The glycerine in some of the jars looks like it may have been diluted (or else have absorbed some water), as it doesn't look as syrupy as it could. 
> 
> These specimens need to be rehoused to new glass jars (they are currently in old plastic containers probably dating back to the 60s or 70s).  Some of them will require topping up. My first thoughts are to place them in their new jars in pure glycerine, but I would appreciate any thoughts or advice on this topic. I really don't want to create a new problem by trying to solve an old one!
> 
> Thanks so much!
> 
> Cheers,
> 
> Tonya
> 
> -------------------------------------------------
> Dr Tonya M. Haff
> Collection Manager
> Australian National Wildlife Collection
> CSIRO
> +61(0)419569109
> https://www.csiro.au/en/about/facilities-collections/collections/anwc
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