Vermicompost tea after 8 days of aeration.

[lperepol]

At 20X, a 40X Objective bends the coverslip on a concave slide.

Looks like a nematode survived 8 days of aeration at 15° to 20° c temperature.

Very small critters in there!

[75RR]

... a 40X Objective bends the coverslip on a concave slide.

That would happen if you are focusing on bacteria at the very bottom of the well slide.
Well sides are quite useful to observe mosquito larvae and other very large (in microscopic terms) beasties with a low magnification objective.
Anything small will take advantage of the extra depth and just swim in and out of focus - quite frustrating.

[lperepol]

Even at 40x with no well slide, the organisms are just shadows shooting around.
What kind to the medium can they be mounted in that will dry with no air bubbles?
Would something like glycerol work?
Or just let them dry on a slide without a coverslip then apply coverslip after drop dries?

[75RR]

If the beasties are large enough you can pin them with the cover slip as the water evaporates.

If what you want is to slow things down across the board then you can use charlie g's slow'm down recipe: 50/50 (half specimen fluid + half 1.5% concentration methyl cellulose)

https://www.homesciencetools.com/produc ... ose-30-ml/

[lperepol]

Thank you for the help 75RR!!
I'll order some concentration methylcellulose.