How to remove fungus from 100 year old diatom slides

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deBult
Posts: 129
Joined: Tue Jul 16, 2019 3:20 pm

How to remove fungus from 100 year old diatom slides

#1 Post by deBult » Tue Sep 22, 2020 6:43 pm

May I ask your combined knowledge for assistance please.

I bumped into a box of 85 old Diatom slides. Age unknown but the glass of the slides looks and 'feels' very old (typical streaks like you see in windows panes begin 1910).
Descriptions in Chinese ink or in pencil. All slides show different Diatom samples - most from the UK and some from New Zealand. Very well cleaned diatoms, mounted with xxx? and the thickness of the mounting layer is a bit on the high side. Coverslips appear to have a variance in thickness as well.

Nearly all slides are full of fingerprints and have a slight cover of fungus on them. I cleaned the first 5 using soap en water, minding not to touch the stickers with descriptions. Fungus ad fingerprint were easy to remove.

Question 1: what is you guidance in cleaning the rest of the slides. In particular how to prevent h fungus from coming back (the description stickers were not cleaned to prevent damage .. so still contain some of the fungus fibers).

Question 2: Some slides have a lacquer? ring around the coverslip: the rings show severe damage. How to salvage them (or alternatively leave as is?)

Best, Maarten
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Scarodactyl
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Joined: Sat Mar 03, 2018 9:09 pm

Re: How to remove fungus from 100 year old diatom slides

#2 Post by Scarodactyl » Fri Sep 25, 2020 12:42 am

For avoiding future growth keeping them away from fungus-promoting environments might be sufficient. Mold spores are everywhere, you just have to make sure they don't get a nice humid environment (helped by temperature swings causing condensation).

Element 56
Posts: 277
Joined: Thu Oct 13, 2016 3:48 pm
Location: Lancaster County, PA

Re: How to remove fungus from 100 year old diatom slides

#3 Post by Element 56 » Fri Sep 25, 2020 6:35 pm

I've gotten old slides with fungus and I used 5% hydrogen peroxide or 5% bleach to make sure I kill it. I treat the paper labels too and yes it can loosen them requiring repair. If the spores are active you don't want that around your equipment so IMO it must be dealt with. This includes the box they came in. When you experience a mold problem in your home you will no longer take chances no matter how seemingly small!

Maybe an alternative would be UV light but you would need to know what you're dealing with to be sure you've killed it (assuming it's still a threat).

Kirby

deBult
Posts: 129
Joined: Tue Jul 16, 2019 3:20 pm

Re: How to remove fungus from 100 year old diatom slides

#4 Post by deBult » Fri Sep 25, 2020 8:00 pm

Tnx for the guidance.

Had already replaced the original box.
Will try a woman's nail UV clearing unit and see how much the labels suffer.

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