Inverted inquiry

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Plasmid
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Inverted inquiry

#1 Post by Plasmid » Tue Jan 19, 2021 6:22 am

Lately I've been considering purchasing a used inverted Microscope, my question is... are the objectives 0.17 just like upright microscopes, and are they LWD?. I just cant picture how the cover slip is held in place specially on a wet mount with the slide sitting upright.

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Dmi3n
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Re: Inverted inquiry

#2 Post by Dmi3n » Tue Jan 19, 2021 10:28 am

Hello. As far as I know the biological inverted microscopes are used mainly for obsersation of cultures inside Petri dishes so the objectives are corrrected not for 0.17 but rather 1-2mm layer of glass. So I guess you can try to view a slide placing it the classic way, coverglass up. And yes, the objectives are usually LWD and the condenser also is - for more comfortable working experience.
Scopes: CZJ NfPk w/ 45mm apo objectives, Phv phase contrast, Epi Pol illuminator, trinocular head, CZJ Epityp-2 Pol (currently dismantled for full restoration and recollimation) w/ D32 microhardness tester and photomicrography attachment.

MicroBob
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Re: Inverted inquiry

#3 Post by MicroBob » Tue Jan 19, 2021 3:23 pm

I just have a basic Olympus Ck with max 20:1 objective and only coarse focus and bicycle lamp. It can be used through the bottom of a slide or petri dish. There are higher power objectives that work through the bottom of petri dishes, like the 32:1 Leitz, but the higher the power the rarer these objectives will be. If you don't have a 40:1 or higher special objective you can build your own observation tray. With a bigger cover slip as the bottom and a piece of plastic or whatever to reinforce and form a vessel. Some people really like their inverted microscopes once they get to know them. Especially for selectively extracting plancton forms the good access from above is worth a lot.

Such a Vessel can be made with a 3D-printer too: https://www.thingiverse.com/thing:3068750

Bob

jmp
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Re: Inverted inquiry

#4 Post by jmp » Tue Jan 19, 2021 4:38 pm

Adding to what others have said, you'd also would need to keep in mind that the aperture of the system might be limited, likely by the maximum NA of the condenser. I would say that this is typically the case of inverted microscopes used mainly for tissue culture, with a fixed condenser of an NA somewhere between 30 to 45, that would typically be equipped with LWD objectives of low to medium power (say 2x to 20x). On the other hand Inverted microscopes intended for research would not have this limitation and would often work with high power, high NA objectives, corrected for a specific coverglass thickness, that would require samples to be mounted in an inverted slide (coverglass down) or special culture plate with a coverglass window in the bottom. As you'd imagine those differences translate into the price range for instruments on each of those two classes.

That being said, I have an inverted LOMO microscope designed for tissue culture, and I really like it in spite of its limitations. It was a bargain, had all the accessories for phase contrast, plus the easy access to the focal planes to sliders made it easy to 3d print custom sliders for oblique, VAC, polarization filters, darkfield. A lot of fun to use and work with. Really convenient to study samples kept in petri dishes for long periods of time. The main drawback, for this instrument at least, is a max 20x LWD and a condenser with a fixed NA of 0.35. But then if I want more detail, I just take a sample from the petri dish to prepare a slide, and then view it in an upright microscope at higher magnification.

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Re: Inverted inquiry

#5 Post by BramHuntingNematodes » Tue Jan 19, 2021 8:56 pm

you can buy like maybe a 10-pack if coverslip-bottom dishes for $50 or if you are cheap like me cut out the bottom of a blister package like this:
Image
and glue on a coverslip to the bottom outside of it with clear silicon sealant just like you can find at the hardware store. I had a little pond critter aquarium like this once I kept topping off with water from my dehumidifier that went on for many weeks until I forgot to water it and it dried up.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Charles
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Re: Inverted inquiry

#6 Post by Charles » Wed Jan 20, 2021 1:09 am

Plasmid wrote:
Tue Jan 19, 2021 6:22 am
Lately I've been considering purchasing a used inverted Microscope, my question is... are the objectives 0.17 just like upright microscopes, and are they LWD?. I just cant picture how the cover slip is held in place specially on a wet mount with the slide sitting upright.
The majority of the objectives should be LWD as well as the condenser but not really necessary for 10X or lower magnification. The condenser normally has an NA of 0.63, so you could use a magnification of 40X. The Zeiss inverted 160mm TL has a 40X NA 0.60 with a correction collar.

Plasmid
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Re: Inverted inquiry

#7 Post by Plasmid » Wed Jan 20, 2021 1:57 am

Thank you all, The microscope I was considering purchasing is a Nikon TMS, has 4-20x pH objectives, but no mechanical stage,. After doing some more digging into inverted platforms , I came to the conclusion that they are not for me, specially for mostly looking at pond water, Anisotropic materials etc.

EYE C U
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Re: Inverted inquiry

#8 Post by EYE C U » Thu Jan 21, 2021 12:51 am

don't give up

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