How to store solutions for slide preparation

[DeeJay]

I recently bought a rotation microtome and started embedding samples in wax. After sectioning the wax needs to be dissolved and replaced by water. This requires a number of solutions of various solvents. I have tried to store them in small plastic jars that can hold a single slide for processing. It works fine but I have noticed that it is not a good long term solution. It seems that the solvents evaporate through the walls of the jars. After some time the liquid level has dropped significantly and the walls have dents in them. I am wondering how you guys solve this problem. What kind of containers do you use and where did you get them?

[Microscopy_is_fun]

Hi DeeJay,

I had similar issues with xylene and isopropanol, to a lesser extent also with ethanol. In my experience it's mostly snap-fit lids that cause the problem. The solvents slighty swell the polymer of the container, and then the snap-fit does not seal properly anymore. Everything that's closed with a threaded cap works better. Best solution are glass bottles, but lab-bottles made from PE with a proper screw-on cap also work well.

I buy them from a local drugstore which is specialized on chemicals and basic lab-supplies. Alternatively from a mail-order biology supply, and in some special cases from a professional lab-supply, which unfortunately does not serve private customers. Where are you located? Maybe I can provide you with suitable links.

[BramHuntingNematodes]

I have a large collection of Bonne Maman labware. Glass containers with rubber-lined metal screw lids. They work very well except for strong acids which eat at the steel in the lid.

[MicroBob]

Hi,
I use slide transport containers in a holder. The lids have openings which I plug with plugs 3D-printed from PETG. For de-waxing and the alcohol ladder down to water I put two slides at a time, same orientation, in these containers and close the lid. To control the fluid level I mark the right level on at least one container. The amount of fluid is small. I use the xylene for a while and then discard xylene 1, use the old xylene 2 as the new xylene 1 and fill it up to level. The xylene 2 is filled with fresh xylene....
The 3D-printed holder fits into the shown box.

Bob

[Greg Howald]

I use glass test tube with metal screw on lids. This has seemed to reduce the problem
Greg

[DeeJay]

I bought these is bulk but they can't handle the solvents (d-limonene, xylene, toluene and EtOH):

plastic jar.jpg (88.2 KiB) Viewed 3809 times

I am contemplating using these

glass jar.jpg (94.43 KiB) Viewed 3809 times

. The problem with these is that these are what the capers come in and there is only so many capers that I can eat . So a link to a company that sells suitable jars would be appreciated. I live in the Netherlands by the way. Lab supplies are not readily available to consumers in my country. But I am also struggling to find suitable containers. I want something that can handle the solvents but I'd like small containers that are easy to store.

[DeeJay]

I have a large collection of Bonne Maman labware.

You mean jelly jars? I have one of those too but they are quite big. I also don't eat that much jelly .

[Microscopy_is_fun]

I bought these is bulk but they can't handle the solvents (d-limonene, xylene, toluene and EtOH):

I used the same ones for cleaning off paraffine from glass slides, see image below. They are large enough to fit a glass slide and small enough that you do not need much solvent. I agree that they are not suitable for long-term storage of xylene&Co.I had the same issues as you. In my view for two reasons:
(1) The fact that they are very transparent indicates that the used polymer is rather amorphous. Amorphous polymers, due to their lower density and thus larger distance between the polymer molecules, are known to be sensitive towards diffusion of solvents. This means that the solvents can swell the polymer rather easily.
(2) The swelling warps the container, and in combination with the large threaded cap this negatively impacts the proper sealing of the cap.

In the image you see other containers, which for me caused no problems and seem to work for long-term storage. Glass bottle is certainly ideal, but the polymer bottles also worked vey well for me. They seem to be made from a semicrystalline polymer (I guess PE), as indicated by their more pronounced "haziness". Additionally, the thread for the cap is smaller.

One source for various containers is https://www.biologie-bedarf.de. They ship to private customers in Austria, I guess Netherlands will work, too.

Regarding jelly-glasses: That might work, but I would never store hazardous material like xylene in a food container.

IMG_20220312_sm.jpg (111.67 KiB) Viewed 3799 times

[DeeJay]

Your explanation of the warping effect sounds plausible. I am guessing that the jar on the left in your picture will also be susceptible to warping since it seems to be made of the same material my containers are made of. Is that correct?
I own a few hdpe containers already among which the dropper bottle in the picture. But so far I haven't been able to find containers with a wide enough neck.

[MicroBob]

I have bought 53ml marmelade jars on ebay. The lid is metal and the jar glass and these are practically diffusion proof. But the seal is soft plastic and can of cause let a little diffusion out and can deteriorate depending on the type of solvents. Real chemical jars would be best but I prefer the transport container with their small volume.

[Microscopy_is_fun]

I am guessing that the jar on the left in your picture will also be susceptible to warping since it seems to be made of the same material my containers are made of. Is that correct?

Yes, that's correct. I think those are the same as you have, and I had the same problems.

Since I plan to do some more paraffine-embedding this year, I am also looking for a good solution. Maybe I will use the transparent jars just for cleaning the slides, and store the solvent afterwards in a more suitable container.

Bob's solution also looks very appealing. Alternatively, I might try some "professional" glass containers for cleaning off the paraffine:
https://www.biologie-bedarf.de/products/382131/

and store the used solvents afterwards in a polymer/glass bottle.

[DeeJay]

The jars that MicroBob has are interesting. But the fluid level needs to reach at least half the width of a slide and I am not sure they do.

Ideally You can use the same jar for cleaning an for storing. Pouring over to another container is a hassle and prone to spilling ( in my case anyway ).

I am contemplating getting these:

105122-weithals-100ml-klar-mit-deckel-600x600_600x600.jpg (20.61 KiB) Viewed 3783 times

https://www.glazen-en-potten.nl/fles-me ... l-786.html
The page is in Dutch but the measurements are on the bottom of the page. I am not sure I will be able to put my thumb and index finger in the opening. I have small fingers but it is still a tight squeeze.

or these:

104592-universal-kunststoffdose-100ml-600x600_600x600.jpg (12.62 KiB) Viewed 3783 times

https://www.glazen-en-potten.nl/univers ... l-336.html
These are polypropylene and are supposed to be solvent resistant

[DeeJay]

@MicroBob, what do you use the pan for? Is it in use as a paraffin stretch bath?

[MicroBob]

The cast aluminium cooking pot is my paraffin oven. It sits on top of a heat plate, air is circulated to increase melting speed without the paraffin getting too hot. The bottom of the pot was a little hollow so I coated it with a layer of heat resistant silicone.
Around the pot there is Armaflex for heat insulation. My stretch bath is another cooking pot on the same heat plate, other point of time.

I use the 53ml jars (and mostly bigger ones) for infiltration. They are not high enough for a slide. For the de-paraffining I use the slide containers.

[Hobbyst46]

For short term storage, Falcon polypropylene (NOT polystyrene) 50ml tubes can serve. Although their bottom is pointed, so must be placed in a rack. They are admirably sealed, though over time, volatile solvents will evaporate, depending on ambient temperature. Do not store them in an unventilated cupboard, because slow evaporation does happen and toluene for example is harmful.

For long term storage, the best are definitely glass bottles or jars that are sealed with Teflon-lined screw caps. Usually sold by lab supply houses. Both Schott and Corning brands exist. Not wide mouthed - their mouth is narrower than the main bulk diameter. They come in sizes like 50ml, 100ml and more. Not cheap. Still, over a long time, the seals swell in toluene.

Recently I have met glass Lock-Lock kitchen-storage containers with plastic covers and rubber seals. Never tried one. A rubber seal is due to hold good with EtOH, but toluene and xylene will cause swelling, and some diffusion through the plastic cover is likely.

[BramHuntingNematodes]

I can also recommend Wheaton glass coplin jars, then. Some petroleum jelly on the rim will make them airtight.

[Microscopy_is_fun]

Ideally You can use the same jar for cleaning an for storing. Pouring over to another container is a hassle and prone to spilling ( in my case anyway ).

I am contemplating getting these:

or these:

You are right, swapping the contents of the containers is somehow a hassle. If you try out the containers which you mention in your post, lt us know how they work. Seems quite a few here are looking for a perfect solution for this application.

[DeeJay]

lt us know how they work. Seems quite a few here are looking for a perfect solution for this application.

Will do. I just placed my order.