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I’m a noobie so I have no experience in mounting microscope slides, however, I had an idea that might be useful and I was wondering if anyone had tried this to see how it works.

I’ve come across a few instances where clear nail polish was used to mount slides and Walter Dioni also has an article on the web. microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/art ... olish.html

Over the long term nail polish may not be satisfactory, but in the short term seems to be pretty good. The use of nail polish for mounting made me think that “acrylic mediums” may work as good as nail polish or maybe even better.

As a painter using acrylic artist paint I am aware that there is a large assortment of acrylic polymers used to modify acrylic paint and are typically marketed as “mediums.” Companies such as Liquitex and Golden sell a whole range of these mediums in convenient and reasonably priced sizes, for example Liquitex Gloss Fluid Medium 250ml/8.79oz for $8-$10. Gloss fluid medium is a medium that has fewer ingredients than many of the others and also has many physical properties most suited to slide mounting:

- dries clear
- fast drying
- high adhesion qualities, adheres to most flexible and rigid surfaces
- the main ingredient is an acrylate polymer acting as a binder
- other ingredients are typically stabilizers and defoamers
- most acrylates have a low refractive index of around 1.50
- highly durable
- can be thinned somewhat with water
- minimal shrinkage

I know that these physical properties don’t address how a medium will react with a specimen or with a stain, but I was hoping someone has tried it out or is willing to give it a try. Liquitex Gloss Fluid Medium is also sold in a thicker Gloss Gel Medium.

Neutral gum

When you search for the above keywords on Chinese shopping sites, you will find price differences close to 5 times, even when the same merchant .....

Ahem, now that's an "opaque commodity"

No reason not to try it.
Drying involves the solvent being lost at the edge of the coverslip.
A clear epoxy would set, possibly making it more stable.

"Drying involves the solvent being lost at the edge of the coverslip." - I didn't think of that. Not being exposed to open air might be the end of my "good" idea.

I tried nail varnish for plant sections. Didn't work, chlorophyll lost it's colour over a period of about 2 months.

Roldorf wrote: ↑

Sat Oct 22, 2022 5:27 pm

I tried nail varnish for plant sections. Didn't work, chlorophyll lost it's colour over a period of about 2 months.

Permanently preserving the color of chlorophyll in a plant section slide seems like a really tall order, maybe impossible. Does anyone know of any way to preserve a plant section along with the chlorophyll at the same time in a permanent mount? I don't know of one. Most folks want to get rid of the chlorophyll and clear the sample...

You might want to see this old post:
"Another Moss Dissection" by forum member mrsonchus (a great expert on plant microscopy and slide-making), on November 2018.
Response #24 on that post sort of answers your question (though not necessarily the best answer...).
PVA (poly vinyl alcohol) seems to be a relatively good mountant.

Right now (October 22, 2022, 21:40), I pulled out the slide of moss I prepared on December 2018 with PVA-acetate-copper, and sealed around the coverslip with nail polish (or gel nail polish (which is better IMO) - can't remember.
So :
1. the moss cells and "leaves" are still green, though not as vivid as fresh moss
2. many of the cells seem to be somewhat deformed and devoid of chloroplasts - probably the latter have been destroyed by bacteria or fungus (not that I see any of those). But I am not sure that the deformation did not happen shortly after the mounting.

In retrospect, sterilization of the mounting media and slide might have helped to prevent deterioration, although that might be difficult in a home lab; besides, the plant itself cannot be sterilized...

Another potential problem is trapped air bubbles among the leaves and in the medium, so degassing might help.

Hobbyst46 wrote: ↑

Sat Oct 22, 2022 6:41 pm

You might want to see this old post:
"Another Moss Dissection" by forum member mrsonchus (a great expert on plant microscopy and slide-making), on November 2018.
Response #24 on that post sort of answers your question (though not necessarily the best answer...).
PVA (poly vinyl alcohol) seems to be a relatively good mountant.

Right now (October 22, 2022, 21:40), I pulled out the slide of moss I prepared on December 2018 with PVA-acetate-copper, and sealed around the coverslip with nail polish (or gel nail polish (which is better IMO) - can't remember.
So :
1. the moss cells and "leaves" are still green, though not as vivid as fresh moss
2. many of the cells seem to be somewhat deformed and devoid of chloroplasts - probably the latter have been destroyed by bacteria or fungus (not that I see any of those). But I am not sure that the deformation did not happen shortly after the mounting.

Very interesting. I will check out the thread. Is the copper acetate with the PVA intended as a preservative/fixative? Was there no other fixation than placing it in PVA with copper acetate?

I recall a very old article about using copper salts (I think?) to artificially color preserved plant sections to appear like chlorophyll. I doubt that is what is happening here, but I will see if I can find it.

I've used PVA on a few occasions for leaflet whole mounts (cleared in Visikol or Hoyer's) under large cover slips. It's pretty good stuff in that application up to a point. I found on a large mounts it tended to suck down disproportionately in the center as it solidified, dishing the cover glass and sometimes causing it to break.

Nope, scratch that. Now that I think about it, it was a PVP mountant that did that.

I think that the copper, together with the acetate, was suggested as anti-bacterial or anti-fungus.
And never did a systematic check if those ingredients are important - just blindly followed a recommendation.
PVA - based glue was suggested by Walter Dioni.

I did not fix the moss or alga specimen. Just rinsed in water, placed on the slide, added the mountant, covered with coverslip, left to dry, then sealed.

For sealing:
Gel nail polish is a good sealant, I cure it under UV from a small cheap (15x8 cm) nail polish lamp.
Ordinary nail polish can be used too.
Nail polish contains volatile components, some of which dissolve in water, and tend to creep under the coverslip by capillary, so they can damage the specimen if applied before the rim of the mountant solidifies.

Copper salts are blue or green or turquoise in color, can it mimic the color of chlorophyll ? I doubt it because the colors are pale, unless the concentration of the salt is high. Then the osmotic pressure would play a role... ?

I did not know that PVP could be used as mountant.

Oliver has a video on using PVA as a mounting medium on one of his youtube channels, check it out.

Hobbyst46 wrote: ↑

Sun Oct 23, 2022 7:39 am

I think that the copper, together with the acetate, was suggested as anti-bacterial or anti-fungus.
And never did a systematic check if those ingredients are important - just blindly followed a recommendation.
PVA - based glue was suggested by Walter Dioni.

I did not fix the moss or alga specimen. Just rinsed in water, placed on the slide, added the mountant, covered with coverslip, left to dry, then sealed.

For sealing:
Gel nail polish is a good sealant, I cure it under UV from a small cheap (15x8 cm) nail polish lamp.
Ordinary nail polish can be used too.
Nail polish contains volatile components, some of which dissolve in water, and tend to creep under the coverslip by capillary, so they can damage the specimen if applied before the rim of the mountant solidifies.

Copper salts are blue or green or turquoise in color, can it mimic the color of chlorophyll ? I doubt it because the colors are pale, unless the concentration of the salt is high. Then the osmotic pressure would play a role... ?

I did not know that PVP could be used as mountant.

We used to seal slides with ordinary (usually dark red!) nail polish in the research lab I was in - needed a steady hand a little skill/practice to get just right! It worked pretty well though.

Louise

Hobbyst46 wrote: ↑

Sun Oct 23, 2022 7:39 am

I think that the copper, together with the acetate, was suggested as anti-bacterial or anti-fungus.
And never did a systematic check if those ingredients are important - just blindly followed a recommendation.
PVA - based glue was suggested by Walter Dioni.

I did not fix the moss or alga specimen. Just rinsed in water, placed on the slide, added the mountant, covered with coverslip, left to dry, then sealed.

For sealing:
Gel nail polish is a good sealant, I cure it under UV from a small cheap (15x8 cm) nail polish lamp.
Ordinary nail polish can be used too.
Nail polish contains volatile components, some of which dissolve in water, and tend to creep under the coverslip by capillary, so they can damage the specimen if applied before the rim of the mountant solidifies.

Copper salts are blue or green or turquoise in color, can it mimic the color of chlorophyll ? I doubt it because the colors are pale, unless the concentration of the salt is high. Then the osmotic pressure would play a role... ?

I did not know that PVP could be used as mountant.

Copper for preserving chlorphyll color:

https://www.jstor.org/stable/pdf/2464571.pdf
https://www.jstor.org/stable/45205006

Interesting that they thought the copper formed a complex with the chlorophyll.
Mostly for dried specimens it looks like, not sections. You are probably right that osmotic pressure would have to be balanced to preserve any delicate cell structure.

PVP makes pretty good mounting medium by itself, totally non-toxic and no volatiles. It's a little yellow. It's very typical to see it used in commercial immunofluorescence media, sometimes pre-mixed with DAPI and/or an antifade additive.