Subjects and method for dry mount, no cover slip?

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zondar
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Joined: Sun Mar 05, 2023 9:11 am

Subjects and method for dry mount, no cover slip?

#1 Post by zondar » Thu May 18, 2023 2:43 pm

Dear forum members,

I need suggestions for one or two interesting and pretty subjects to view, and advice about mounting them.

* Needs to be a dry subject that won't decay.
* Should be a broad or continuous subject that doesn't need to be searched for.
* Should be thin and transparent enough for good viewing with transmitted light.
* Should be a subject that is interesting or pretty to view at about 50x magnification.
* Needs to be mounted to glass without a cover slip.

And finally, how to mount it with some permanence?

Thank you!

Jose Antonio Mena
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Location: Santander

Re: Subjects and method for dry mount, no cover slip?

#2 Post by Jose Antonio Mena » Thu May 18, 2023 6:01 pm

Hi

Blood smears

different crystallized substances.

There is a very good book from Bruno Kremer, that can inspire you.

Regards

JA

zondar
Posts: 22
Joined: Sun Mar 05, 2023 9:11 am

Re: Subjects and method for dry mount, no cover slip?

#3 Post by zondar » Mon May 22, 2023 8:03 pm

Thanks.

Important point that bears repeating: The view will be at 50X total magnification only. No possibility of any other magnification. Also, no possibility of using a cover slip or to scan the surface for something interesting.

For testing purposes, I am currently using a streak of dry marker on the glass, but that's not interesting enough to show others.

I think blood cells might just barely be visible at 50x total magnification, but not as more than very tiny featureless dots, no? If someone looked at it and guessed blood cells unprompted, that could do, and a dried smear should be OK without a cover slip (albeit easily destroyed).

Maybe a bit of onion skin? That should be thin enough to pass some light, and I think the cells should be visible. But how to mount it without a cover slip?

What else might do?

This is for a somewhat unusual project, which I'll show here when done. I only need one or at most two subjects for others to view on rare occasions.

Thanks again.

Hobbyst46
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Re: Subjects and method for dry mount, no cover slip?

#4 Post by Hobbyst46 » Mon May 22, 2023 8:29 pm

Certain plant or insect parts could serve as semi-permanent specimens. They will be good for at least a few years.
For example, mosquito wings.
Or the pappus ("parachute") of the seeds of certain plants, those that are carried and spread by winds, where they drift gently in the air.
Both can be mounted in transparent nail polish without coverslip. Nail polish is RELATIVELY resistant to ambient temperature and humidity.
It will take some practice to prepare the slides without air bubbles. Try to spread the thinnest possible layer of nail polish on the slide.

Onion skin is suitable for wet mounts. In nail polish it is liable to fold over, shrink and look ugly. In addition, when unstained, its image is not very crisp and nice.
Fixing and staining the onion skin is possible, yet again, AFAIK, mounting it in a medium without coverslip will be problematic.

zondar
Posts: 22
Joined: Sun Mar 05, 2023 9:11 am

Re: Subjects and method for dry mount, no cover slip?

#5 Post by zondar » Mon May 22, 2023 8:38 pm

Thanks, the "seed parachute" idea seems quite interesting. I'll scan the area around my home for possibilities.

There are very few mosquitos where I live, thankfully, but I'll look around my residence for a dead spider or something like that.

My "slide" is actually a 10mm optical window of borosilicate glass, and I only have two at the moment (they are expensive). I suppose nail polish can be removed with lacquer thinner, etc., if I mess up too badly.

Hobbyst46
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Re: Subjects and method for dry mount, no cover slip?

#6 Post by Hobbyst46 » Mon May 22, 2023 8:49 pm

zondar wrote:
Mon May 22, 2023 8:38 pm
Thanks, the "seed parachute" idea seems quite interesting. I'll scan the area around my home for possibilities.

There are very few mosquitos where I live, thankfully, but I'll look around my residence for a dead spider or something like that.

My "slide" is actually a 10mm optical window of borosilicate glass, and I only have two at the moment (they are expensive). I suppose nail polish can be removed with lacquer thinner, etc., if I mess up too badly.
Yes, nail polish can be removed with acetone as well. Is the window coated ?
A spider has no wings. I suggested wings because they are transparent and display interesting features under trans-illumination.
No mosquitoes ? sounds like paradise. no house fly or some other flying insect ?

zondar
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Joined: Sun Mar 05, 2023 9:11 am

Re: Subjects and method for dry mount, no cover slip?

#7 Post by zondar » Mon May 22, 2023 9:16 pm

Southern California is very dry, which really cuts down on them. I wouldn't call it paradise, but it's a big bonus. That tiny whine immediately launches a DefCon-5 seek-and-destroy mission, with no possibility of sleep until it's terminated.

Yes, I agree an insect wing would be a very good subject! I'll keep looking (so far only a old desiccated spider carcass was found).

I'll go look and see if I can find a flowering dandelion - that could work too.

Thanks for the ideas!

(Edit: The windows are uncoated, and I do have some acetone.)

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patta
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Re: Subjects and method for dry mount, no cover slip?

#8 Post by patta » Mon May 22, 2023 10:46 pm

While trying to mount diatoms, I've tried this:
Filter pond/seawater with coffee filter
squeeze the the result on the glass
let it dry
If the sample was nice there will be full of algae and microrganisms, stuck to the glass. Usable; with coverslip then gets better and more robust.


Did you try Uni-Posca pencils
or wall paints?
They have very fine grains that look decent at high magnification

zondar
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Re: Subjects and method for dry mount, no cover slip?

#9 Post by zondar » Wed May 24, 2023 5:15 pm

A little follow-up:

I nicked myself shaving this morning, so I put a tiny smear of blood on my little 10mm "slide." At ~55x, yes, I could see blood cells as pale, basically featureless dots. I'm not sure anyone would guess what it was without a prompt, but I'll leave that slide as-is for now.

Thanks for the suggestions.

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