KOH vs Cedarwood Oil; Cleaning vs. Clearing

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TonyT
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Joined: Fri Sep 11, 2020 8:30 pm
Location: New Brunswick, CANADA

KOH vs Cedarwood Oil; Cleaning vs. Clearing

#1 Post by TonyT » Wed Oct 27, 2021 1:10 pm

In a recent post:
viewtopic.php?f=10&t=14059
Viktor asked about combining both for small flies.
KOH is more of a cleaning agent than a clearing agent. It dissolves cellular contents with little effect on chitinised structures. Such cleaning does result in a clearer specimen.
Cedarwood OIl and similar agents do not dissolve cellular contents but render them and chitinised structures transparent.

A protocol for using both:
1- clean specimen in KOH
2- thoroughly wash in water to remove KOH, be wary of using a weak acid as it may form CO2 bubbles in the specimen.
3- arrange wings and legs and dehydrate in alcohol (99+%)
4- remove as much alcohol as possible without letting specimen dry, add a drop or two of clearing agent. Small insects with become transparent within an hour;
can be left indefinitely. Clearing agents will make the specimen extremely brittle!

For extremely delicate objects cleaning is best done with enzymes; easiest source is contact lens cleaner (the ones that use enzymes).

As an example of KOH + Cedarwood Oil: a small wasp was entangled in the legs of a larger insects in my Berlese funnel extraction. This wasp ended up in 5% KOH. Looked interesting
so I went through the above and it is now in Cedarwood Oil; photographed in the oil. A better image would result if it was mounted in Euparal which also has a clearing effect.
Note how transparent are the legs and the reproductive system.
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