Inverted vs. Upright Microscopes

[Pat Thielen]

Hey all,

I'm curious as to what the advantages are to using an inverted microscope, if any, in place of an upright microscope. I actually acquired my very first inverted microscope; a Swift FM-31 field microscope, but I'm afraid it is of rather limited use in the field because you have to view the slides upside-down (that is, with the cover glass down). This won't really work when looking at wet mounts. But I do know a lot of people use inverted microscopes and I'm guessing they generally aren't used in this way. So, what are the advantages of using one?

Just curious. Thanks much!

-Pat

[zzffnn]

Pat,

Inverting slide should work, if you squeeze out excessive water. If it still does not, please sell it to me for a low price

Main benefits of inverted scopes include: 1) subject falls onto covet slip because of gravity, so less water or culture media lies between subject and cover slip to degrade image quality;

2) you have better chance to observe subjects in a more natural environment (when culture dish is used); and

3) they offer more space above sample for sample manipulation. This is a huge benefit in research.

[MicroBob]

Hi Pat,
this topic has been discussed just recently. Do a search for "inverted" and you will find a lot of information.

Bob

[abednego1995]

Hi!

Those swift microscopes are nice, great catch.
If you need to observe wet mounts on a regular basis, making well slides from acrylic or glass
with holes around 10-12mm diameter in the middle with coverslips bonded to the bottom are a nice investment.
Having a few for a trip cuts all the hassle involved with coverslipping in the field.

Cheers,
John

[75RR]

Hi!

Those swift microscopes are nice, great catch.
If you need to observe wet mounts on a regular basis, making well slides from acrylic or glass
with holes around 10-12mm diameter in the middle with coverslips bonded to the bottom are a nice investment.
Having a few for a trip cuts all the hassle involved with coverslipping in the field.

Cheers,
John

Nice idea. I suppose acrylic for the slide is more practical than glass, what adhesive do you use?

[abednego1995]

Nikon used to sell them for their Model H microscopes, but it seems to have been an obscure item since I've never seen one in real life.
Any adhesive would do. I've used silicone, epoxy, even Entellan, but all work OK.

Cheers,
John

[Hobbyst46]

From experience, I would try and get commercial Petri dishes with glass coverslip bottoms. In spite of the initial cost, one can clean them after use and re-use. Can be cleaned with hypochlorite or caustic soda (a low concentration, under safety measures like eye protection) or ethanol.
Self-made dishes are not as good (in general). Cements tend to leak, or otherwise the bottom is not perfectly horizontal. See this previous post and accompanying comments:
viewtopic.php?f=5&t=6490&p=58144&hilit=REZA#p58144

[abednego1995]

Yup, I absolutely agree with getting glass bottomed petri dishes for normal benchtop inverted microscopes. You can't get any better.
However, even the smallest 35mm diameter dishes (are there smaller ones?) it would be very difficult to manipulate on the Swift stage (It's very unforgiving due to its size...)

The cheapest option I use for quick examination on an inverted scope, is to draw a ring with a hydrophobic grease pen (I think it's called a PAP-pen in histology circles.)
on a large coverslip (I use 24x50) and place a drop or drops within the rings which are retained by surface tension. I just chuck the coverslip afterwards.
(If there is something interesting, just dry it, sometimes do staining, and mount it after dehydration like a normal slide.)

[Radazz]

These are nice little scopes! I tried one of the smallest glass bottom Petri dishes I could find, and it’s still really unwieldy in the field. Double sized cover slips work well. I’ve found I really only need to invert a prepared slide when using the 40x objective.
Very nice for a quick check of a sample when collecting.

Just occurred to me, I should ring a couple of the large cover slips.
Radazz

[charlie g]

Hi, Pat ( the OP of this thread), and all who share good insights. My sense is for: 'use of microscopes in the field'..inverted stands offer no advantages to a humble standard cmpd stand.

Why on earth lug delicate :'cover-glass thin bottomed petri dishes into the field ( do you mean a hike to mountain streams, to marie mud flats, to swamp habitats far from where you parked the bike/ or the car on a collection hike?) ? Why not ( for field use that is) obtain 40X LWD objective for the field microscope?

An inverted stand is a very specialized instrument...excellent for mycology culture work, tissue culture work, bacteria culture work...where you observe/manipulate, then return these ongoing cultures to their growth chamber or window ledge for further studies at latter times. The compromizes are large...little abilty for high resolution( high NA objectives/ little ability for high mag/ high NA objectives ...absolutely limited use of oil-immersion, or water-immersion objectives.

Frankly..with even huge flatworms ( a treat to flush out in field observing before specimen collection), with hydras, water fleas..with all sorts of 'naked eye enjoyable meiofauna'...a simple 'depression slide/ a well slide' offers great field observations with: 2X, 4X, 10X, 20X objectives on a humble cmpd stand...and LWD 40X objectives cover the observation needs for 'microscopy outdoors in the field'.

I Have an Olympus CKA inverted stand I purchased 'cheap'! at a NY astronomy three day forum for hobbyists...it has a huge foot print to keep at ready ot my bench..it is wonderful..yet it slumbers boxed up on the shelf with other wonderful stands I have no need for in my sporadic microscopy hobby.

If you are intent on mycology collecting...mycology culture..you still need high mag/ high NA oil-immersion cmpd stand to ID the spores of that organism you culture...tissue culture is almost a rarified academic pursuit due to temp/gas compositions/contaminant preventions...inverted stands are fun..but a highly limited microscope when you consider the overlap of duties an upright cmpd stand offers...and the 'more' the upright stands offer.

Perhaps having said all this...I am willing to low cost sell my Olympus invert stand..and I have a few LWD objectives too, which I can part with.

Different horses for different courses, Pat, but a cmpd stand with 2X, 4X, and 'depression/ well' slides offers most of what an inverted stand offers...and more! Charlie Guevara, finger lakes/ US

[billbillt]

SOME PEOPLE HAVE NO TROUBLE USING A MICROSCOPE OUTDOORS..

[Pat Thielen]

Thanks for all the really great responses -- You've all been very helpful. The advantage the Swift FM-31 has is that it is incredibly small; it practically fits into a pocket. Actually, it would totally fit in a coat pocket. The obvious disadvantage is that the slides generally need to be upside down on the stage to work. I do like the idea of drilling out a slide and mounting a coverglass to the bottom. While this may have some difficulty I think it is quite possible. And, I would only need a few of these slides for it to be practical. Of course, my issue is how to go about drilling a hole into a slide. I'm going to see if I can find plastic slides; those could be easily drilled and would work quite well I would think. And being plastic they wouldn't break in a field kit as glass ones might. Plastic is your friend in this case.

Otherwise, I'll simply carry my Bosch & Lomb with me. I can easily keep it in the car until I have something to look at. While not nearly as portable, it is small and has a mirror and so it is always available to use (no need to plug it in or anything).

Both of these have their strengths and weaknesses. In any case, I am happy to have them. And thanks again for all the very helpful comments; I really do appreciate them.


-Pat

[Hobbyst46]

...I do like the idea of drilling out a slide and mounting a coverglass to the bottom. While this may have some difficulty I think it is quite possible. And, I would only need a few of these slides for it to be practical. Of course, my issue is how to go about drilling a hole into a slide.

I have drilled many glass plates. Even filters. The required tools are:
1. A diamond-tip drill bit. It is a borer bit, the cutting end is a thin-walled hollow cylinder (without blade), coated with diamond powder.
2. A drill press.
3. A retainer pan. Any flat-bottom, low profile metal/plastic pan, that can sit on the press table. Size 25x25x4 cm (say).
4. A scrap glass plate, thickness 5mm, say, that fits loosely inside the retainer pan, and serves as base plate for the drilling.
Place the base plate in the pan. Fill the pan with water, to a depth that just covers the glass plate. Place the pan on the press table. Place the slide on the base plate. Wear goggles that fully protect the eyes, a face-shield would be even better. Protective gloves might be a good idea, although I never used ones. Press on the end of the slide with your finger and drill slowly, under very light pressure, at moderately slow speed. The idea is to cut under water.

I'm going to see if I can find plastic slides; those could be easily drilled and would work quite well I would think. And being plastic they wouldn't break in a field kit as glass ones might. Plastic is your friend in this case.

Drilling poystyrene slides: polystyrene is easily deformed and becomes non-flat due to the heat generated by the drilling.
Note: A Europe-based firm named Ibidi carries an amazing selection of disposable slides with cover-slip bottoms, for cell and tissue studies with inverted microscopes. Multi-wells as well (pun). They are optically perfect, and can often be recycled.

[charlie g]

Hi again, Pat...consider a quick and dirty use of thin plastic ruler..thickness equal to standard microscope glass slides are available...bore a hole then cement a rectangular cover slip over the hole.

Sheet metal also easy to work with to fabricate a few DIY cover glass bottom slides. just a thought, Charlie guevara

[75RR]

Have not used this myself but it looks like this or something like this would make converting glass slides into inverted well slides (by gluing a cover slip over the hole) for the Swift FM-31 field microscope quite feasible.

https://www.amazon.com/BLENDX-Diamond-D ... way&sr=8-5

[Hobbyst46]

Have not used this myself but it looks like this or something like this would make converting glass slides into inverted well slides (by gluing a cover slip over the hole) for the Swift FM-31 field microscope quite feasible.

https://www.amazon.com/BLENDX-Diamond-D ... way&sr=8-5

Wow, those are exactly what I had in mind, only that mine arrived before Amazon was founded...

[abednego1995]

Drilling holes in glass slides sounds like a piece of cake, but in reality,
you realize it's quite hard after a dozen shattered slides (even underwater with those coring bits.)

Wish someone near has a water jet cutter...

[billbillt]

HI,
i HAVE HAD GOOD LUCK BY GRINDING A HOLE IN GLASS WITH VALVE LAPPING COMPOUND AND A DRILL PRESS.. BUILD A SMALL DAM WITH MODELING CLAY AROUND THE AREA WHERE YOU WANT THE HOLE, PUT A DAUB OF LAPPING PASTE IN THE DAM AND SOME MOTOR OIL.. I USED A SHORT, STRAIGHT PIECE OF COPPER TUBING TO "LAP" A HOLE THROUGH THE GLASS...

BILLT

[billbillt]

IF YOU ARE JUST NEEDING "WELL CAVITY" SLIDES. WOULD NOT SOMETHING LIKE THIS WORK?

https://www.ebay.com/itm/5pcs-New-2-Wel ... SwR6RaN2ay

BILLT

[Hobbyst46]

Drilling holes in glass slides sounds like a piece of cake, but in reality,
you realize it's quite hard after a dozen shattered slides (even underwater with those coring bits.)

Wish someone near has a water jet cutter...

I have successfully drilled 3-5mm thick glass plates without breaking, so, not a piece of cake but not a horrible challenge either. Not that I recommend it, if there is an alternative.
Actually, the challenge is not so much the cutting, but the glueing of a coverslip to the slide. I mean, creating a uniform-thickness cement layer, such that the cover-slip is exactly parallel to the slide.

IF YOU ARE JUST NEEDING "WELL CAVITY" SLIDES. WOULD NOT SOMETHING LIKE THIS WORK?
https://www.ebay.com/itm/5pcs-New-2-Wel ... SwR6RaN2ay

I think that the OP looks for really deep, cylindrical wells.

[billbillt]

Drilling holes in glass slides sounds like a piece of cake, but in reality,
you realize it's quite hard after a dozen shattered slides (even underwater with those coring bits.)

Wish someone near has a water jet cutter...

I have successfully drilled 3-5mm thick glass plates without breaking, so, not a piece of cake but not a horrible challenge either. Not that I recommend it, if there is an alternative.
Actually, the challenge is not so much the cutting, but the glueing of a coverslip to the slide. I mean, creating a uniform-thickness cement layer, such that the cover-slip is exactly parallel to the slide.

IF YOU ARE JUST NEEDING "WELL CAVITY" SLIDES. WOULD NOT SOMETHING LIKE THIS WORK?
https://www.ebay.com/itm/5pcs-New-2-Wel ... SwR6RaN2ay

I think that the OP looks for really deep, cylindrical wells.

THANKS FOR THE CLARIFICATION..

BILLT

[abednego1995]

I have successfully drilled 3-5mm thick glass plates without breaking, so, not a piece of cake but not a horrible challenge either. Not that I recommend it, if there is an alternative.
Actually, the challenge is not so much the cutting, but the glueing of a coverslip to the slide. I mean, creating a uniform-thickness cement layer, such that the cover-slip is exactly parallel to the slide.

Yup, I think thicker glass would be more foregiving. I used crown glass slides, might it be easier to use soda lime?

And the parallelism of the coverslip wouldn't be much of a problem when you're maxxed out with 40x NA0.65 objective on the swift.

And Oh.... The Swift instructions points out that the slide should be facing the objective

08B951D7-847E-4D9F-BC85-7F4F30BFE6BD.jpeg (59.53 KiB) Viewed 12735 times

[75RR]

And Oh.... The Swift instructions points out that the slide should be facing the objective

Makes sense ... full name is Swift FM-31 LWD Portable Field Microscope

It also appears that the objectives are non-RMS threaded, which probably means that most of them have the original LWD objectives in place.

[MichaelG.]

Thanks for sharing those instructions

They are very clear [at 2.] regarding the orientation of the slide
... but that leaves me utterly bewildered.

Is this supposed to be a drilled slide [as discussed above], with a wet sample hanging from the coverslip ?
... and if so, why is the coverglass thickness significant ?

MichaelG.
.

Edit: I note that in the concurrent thread, Radazz states:

The 4x and 10x objectives focus correctly through the slide, and the manual says place the slides right side up, but the 40x will only work good through a .17 mm coverslip, so on an inverted scope the slide needs to be upside down for this objective.

That seems perfectly reasonable ... but is it all stated in the manual ??
.

Edit: This, and the referenced document, are both worth a look:
http://www.microscope-antiques.com/fm31.html

[75RR]

My box of slides states that they are between 1mm and 1.2mm thick. There are slides for sale that are as much as 1.5mm thick.

I wonder if that is the reason (i.e. slide is too thick) that it is 'not possible' to focus on the subject with the 40x objective as stated above when the slide is inverted.

[MichaelG.]

I've found the 1994 version of the manual, here:
https://www.microscopeinternational.com ... series.pdf

... are any other versions available ?

MichaelG.

[75RR]

I've found the 1994 version of the manual, here:
https://www.microscopeinternational.com ... series.pdf

... are any other versions available ?

MichaelG.

Note that on page 8 they give slide thickness of 1.0mm. That decimal point looks to be significant, otherwise they just would have said 1mm.

My box of slides states that they are between 1mm and 1.2mm thick. There are slides for sale that are as much as 1.5mm thick.

I wonder if that is the reason (i.e. slide is too thick) that it is 'not possible' to focus on the subject with the 40x objective as stated above when the slide is inverted.