Doing Diatoms

[rnabholz]

Thanks Dave.

I am glad you are enjoying it. I know that I am certainly benefiting from the exchange of ideas with everyone. For example your sand bottle cleaner tip, great idea, thanks for sharing it.

Stay tuned, more to come.

[rnabholz]

I took a look at the stocking fabric under the scope last night.

I would estimate the pore size at about 200 microns, but it is not quite that simple.

While that is a representative measurement of the size of the opening, the weave of the fabric effectively reduces that diameter. The opening is not a sharply defined edge, but is formed by woven strands. Random loops of strands irregularly intrude around the edges and would likely impede the passing of some material.

Add to that the fact that the material is doubled and I would say that the effective pass size is well less than 200 microns.

In my review of the passed material, I did see material , long forms, that I would say were in the 100 micron range in length.

I think that it is performing well, and I have four samples that after soaking in HP overnight look to be more clean and uniform than any I have been able to produce to date. I should be able to get them mounted in the coming days and provide at least one data point.

[zzffnn]

Onto the dollar store for some stockings

Most fresh and salt water diatoms that I have seen at shorter than 200 microns. So that likely works well for most diatomists. One can always stretch the stockings slightly or use just one layer, I guess.

A Frontonia, a Paramecium or a Rotifer can get to 300 microns. An extended Stentor can be longer than that. Most other ciliates and flagellates are a bit smaller. Crustaceans, larvae and worms are usually bigger.

Are there cheap filtration materials with 500-600 micron size?

[rnabholz]

Onto the dollar store for some stockings

I recommend the "Queen Size" for a roomier fit, uh, er, I mean to give you more straining material to work with....... ;^)

[KurtM]

I'm gonna post this here since it has become something of a comprehensive slide making thread: behold my world famous slide template! Seriously, I saw the idea on the web, and gave it a try. The original was very simply made of posterboard, and so was mine. It turned out to be one of those gems that I used so often I wore it out, or at least it got to the point where it refuses to lay flat, which it really needs to do. So today I stopped in at the hobby shop and picked up a sheet of .020" styrene plastic about the size of a piece of paper for $1.75, and a small bottle of thin CA (super glue). Construction should be self-explanatory, see pix below.

Pic 1 shows both the cardboard original, and the new & improved plastic model. Pic 2 shows the new one with a slide on it. Note the side "rails" leave a slightly oversize opening for the slide, this is intentional. Not only is it counterproductive to hold the slide too tightly, but I have found that slide size varies a bit, so this should hold any of them. Took about 15 minutes.

Cutting sheet styrene is super easy; just mark where you want to cut, lay down a straightedge, and use a box cutter to cut a groove. It's called "scoring" the plastic. Then pick up the plastic and bend it along the cut and it breaks easily, but doesn't separate. Bend it back the other way and snap!, it separates cleanly. The hardest part of making this thing was keeping the watery thin CA under control, for which I recommend keeping tissues handy.

Mark the card as you please to locate the slide. Drill a couple holes for hanging. Done!

[rnabholz]

Ya know while you were at the store and had all the tools out it wouldn't have been much more trouble to build another one.....

That is a nice upgrade the the plastic version. This is on the project list. My little paper template will allow the slides to move, an inconvenient "feature".

[KurtM]

Had to take the shiny new template for a test drive, and made another pleasant little discovery you may be interested to hear about while I was at it. A trip to hobby Lobby for a fine tip slide ringing brush also netted a bottle of Testor's gloss black enamel. I didn't know they still made it, all I saw at the model shop was acrylic model paints. Whatever, I tried it today, and it's great - flows off the brush nicely, builds well, is plenty opaque, and dries quickly to a high gloss. I wish I had known about a long time ago.

The top set of six slides is ringed with Michel's "black ringing lack", the bottom six with Testor's gloss black enamel. The brush, which I can also recommend, is labeled "Master's Touch 18/0 7000 Liner".

[rnabholz]

Had to take the shiny new template for a test drive, and made another pleasant little discovery you may be interested to hear about while I was at it. A trip to hobby Lobby for a fine tip slide ringing brush also netted a bottle of Testor's gloss black enamel. I didn't know they still made it, all I saw at the model shop was acrylic model paints. Whatever, I tried it today, and it's great - flows off the brush nicely, builds well, is plenty opaque, and dries quickly to a high gloss. I wish I had known about a long time ago.

The top set of six slides is ringed with Michel's "black ringing lack", the bottom six with Testor's gloss black enamel. The brush, which I can also recommend, is labeled "Master's Touch 18/0 7000 Liner".

Woo Hoo I got a Hobby Lobby 20 miles a way- Road Trip!

Those look really great Kurt. Those labels are getting to me....really professional looking. Of course the Backwater RedNeck look of my hand written ones have a certain primitive charm.

That is one super fine brush you have there.

Did you employ the mineral spirit thinning with the Testors paint?

Do you apply multiple layers? Do you wait between layers?

Great work.

[KurtM]

The most highly sought after classic antique diatom slides from the famous Victorian makers sport handwritten labels. I actually love handwritten labels, but it's just plain difficult for me to write that much information, that small, over and over again, not to mention certain logistics like finding suitably fine point pens that are reliable and durable enough to keep going for as long as you need 'em - it ain't as easy as it sounds. Yeah, the label printer has been a godsend.

You ask excellent questions on points I should have addressed from the start: one of the main things we look for in a good ringing cement is the ability to use it straight from the bottle. YES, the Testor's works straight from the bottle, no thinning necessary. Another big deal we want is good coverage, so second coats aren't necessary. Actually, I apply about three or four coats, but all in one session, so only one trip to the ringing table per slide. Basically I just keep applying paint till it looks good, then ... next!

[rnabholz]

Excellent, thank you for the run down. Definitely gonna pick up a bottle of two and a new brush.

[rnabholz]

We have mentioned using Potassium Dichromate in the cleaning process, and so I would like to share my experience with it, hopefully to save some of you some trouble.

When added to 35% Hydrogen Peroxide, the resulting reaction is immediate. Here's a quick video



This HP had been cleaning the diatoms in that flask for 24 hours, so one could argue that it had already expended much of its energy.

As you can see, it takes very little PD to do the job, even with the weakened HP.

Do not be fooled by a what appears to be a slow start to the reaction. In my experience, it can take many minutes for the reaction to peak.

RESIST THE URGE TO ADD MORE POTASSIUM DICHROMATE TO THE SOLUTION!

If it sounds like I might have some negative experience guiding my advice, you are absolutely correct. I had half a sample just like the one pictured boil out the flask after adding a second portion of PD to what I thought was a non reactive sample.

It took nearly 5 minutes for it to take off, but when it went, it really went! Fortunately, the sample was caught by the tray, and I was able to recover it.

When the reaction is over, the mixture will turn from the dark purple color to orange. I then heat the mix in a water bath of around 160F for a couple hours and after that it is on to rinsing.

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So my advice in summary

1. Use a larger container like a flask or breaker, a test tube does not offer much room for error.

2. Have a way to catch overflow in the event it becomes necessary. A tray or bowl can do the job.

3. Be conservative in the amount of PD used. The video demonstrates how little I used in nearly 50ml of solution. Go slow.

4. If the solution turns dark purple, you have the reaction you are looking for, let it work.

5. Do not heat the solution until after it has turned orange. Heating it earlier will accelerate the reaction, and perhaps cause it to get too energetic.

6. Patience! The reaction can be slow to develop. Do NOT add more PD.

I hope my experience can help you avoid any issues.

[rnabholz]

Back with some results on the Strainer.

Below are 40x full fields from the last two batches processed through the strainer. Afocal with the phone camera

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StrainerTest2.JPG (113.37 KiB) Viewed 518418 times

StrainerTest3.JPG (143.97 KiB) Viewed 518418 times

Notice that while there is still deritus in the fields, the particle size of the matter is quite small, and there seems to be a very significant reduction in occurence of big "clumps" that I had seen in previous batches.

I intentionally selected fields showing some of the larger forms. The largest are approximately 100µm in length and did pass. Not only did they pass, but did so without damage and some of those thin forms would have to be quite delicate.

There seems to be a good variety, and it compares very favorably with previous batches from similar regional rivers.

On practical level, the batches cleaned well and relatively quickly. The cleaned sample appears to the naked eye to have less sand and grit that settles out after agitation.

While I did not check on what was strained out, an oversight that I intend to correct on the next opportunity, I can absolutely say that there will in fact be a next time, as I think the results show it to be worth the effort. If I find interesting things in the filter material, I can always run dual tracks in the cleaning process.

[exmarine]

Hey guys,
I have never re strained the muck left on the tights to me its just not worth the effort for a poor to no diatoms showing.
I am glad you did a great job on straining as it reflects in the photo's above. I would be pleased with the outcome as to be able to identify every diatom on the photo's would be easy. All I can say Rod is well done sir, well done.

[zzffnn]

Great work, Rod. It turned out really well!

[rnabholz]

Hey guys,
I have never re strained the muck left on the tights to me its just not worth the effort for a poor to no diatoms showing.
I am glad you did a great job on straining as it reflects in the photo's above. I would be pleased with the outcome as to be able to identify every diatom on the photo's would be easy. All I can say Rod is well done sir, well done.

A big thanks to you exmarine! It was your presenting the idea here that made me aware of the technique and caused me to try it. I consider it a key step in my process going forward.

I am really pleased with the results, and of course the best part is it didn't require much time and less than $3 in cost. That doesn't happen often in this hobby.

Thanks again for following along, and please keep throwing out those nuggets anytime the spirit moves you..

[rnabholz]

Great work, Rod. It turned out really well!

Thanks zz!

[exmarine]

Hi Guy's,

Now all we have to do is name the diatoms and give the Genera and species if possible. No I do not intend to comment on what I would consider certain diatoms to be, I'll leave that to you Rob seeing as they are your diatoms.

My next step in the procedure would be to set up my Phase Contrast microscope using the X100 oil immersion objective. I would study different sections of the individual diatom to gain the characteristics of the raphe, the nodules, and most importantly the striae followed by the approximate size. This should give me the genus and hopefully I could deduce the species. In the instance of your photo's I would only go for the most prominent diatoms. Then I would label my slides up accordingly. Simple yeh!

I must try and get this uploading of photo's done as I have been given an idiots guide, really I am as thick as two short railway sleepers.

Rod can I have your permission to download your photo's into my collection of diatom slides and photo's?

[rnabholz]

exmarine,

I am flattered, yes you have my permission to download my photos for your own personal or non-commercial use.

I have been working on my ID skills as I hoped you had noticed in some of my photo postings, not so much on the darkfield yet, as I was playing with a new toy and too busy flitting around the slide.

Thanks for the guidance on an orderly study. I will see what I can do.

Rod

[rnabholz]

Did some slide making yesterday.

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I got a chance to use the Testor's Enamel paint and new brush recommended by Kurt - A wonderful combination! So much easier than the Rustoleum and the required thinning. This stuff worked straight out of the bottle and behaved perfectly. The small brush offered much better control. A big improvement all around. Thanks Kurt!

One tip I would offer for those going out to look for this stuff is the crazy labeling on the bottle. Please note the red line at the top of the label (which Hobby Lobby did its best to try and hide).

TestorsEnamel.jpg (86.82 KiB) Viewed 518374 times

That is the only place on the label or display rack that indicates that this is enamel and not acrylic, and the red stripe only appears on one side of the bottle. I stood there for five minutes looking at every bottle of black paint until I finally noticed it. DOH!

Now if you will excuse me, I have eight new slides to explore....

RingedSlides5-29-16.jpg (124.06 KiB) Viewed 518374 times

[KurtM]

Hey, those rings look great, and there's a lotta fun and satisfaction in it too, I bet! Mighty glad to hear my recommendations delivered - whew! - always a bit of a worry. Yep, I couldn't believe it when, on my last trip to H-L, I just happened to look in the right place at the right time and notice the rather subtle Testor's enamel display, had become pretty well convinced that actual old-time oil-based model enamels were a thing of the past. The smell brings back memories, eh? I shoulda bought some of the red-orange label plastic model cement just to see if it's the real deal...?

Hey, I got a couple new brushes, the ones Michel recommended arrived yesterday evening, pretty amazing since they came from Belgium and I only ordered 'em last week. I have new slides to ring today, will issue a report once I have given one a test. Tiniest things I ever saw, dang near need a microscope to see the tip!

[billbillt]

Hi Kurt and Rod,

Let me ask my dumb question: What is the purpose of the "ringed slides?... I have seen antique slides done this way and see them as very cool... Is eye appeal the only purpose?.. Or is there some other added benefit that I can't see..

Thanks,
BillT

[KurtM]

Bill, that's an excellent question I meant to address. In this particular case, it's ornamental, as properly cured Pleurax is stable and impervious. But for other types of mounts such as glycerin jelly, for instance, ringing serves to seal the gap between slide and cover slip to prevent drying out, alcohol incursion, things like that. Ringing can also secure cover slips on dry mounts. While normally thought of as cover slip sealant, it may be used simply to put a finishing touch on the slide maker's work.

Short answer: it's fun!

[billbillt]

Thanks for the quick reply, Kurt.. Do you also use round cover slips exclusively with ringed slides?

BillT

[rnabholz]

Hey, those rings look great, and there's a lotta fun and satisfaction in it too, I bet! Mighty glad to hear my recommendations delivered - whew! - always a bit of a worry. Yep, I couldn't believe it when, on my last trip to H-L, I just happened to look in the right place at the right time and notice the rather subtle Testor's enamel display, had become pretty well convinced that actual old-time oil-based model enamels were a thing of the past. The smell brings back memories, eh? I shoulda bought some of the red-orange label plastic model cement just to see if it's the real deal...?

Hey, I got a couple new brushes, the ones Michel recommended arrived yesterday evening, pretty amazing since they came from Belgium and I only ordered 'em last week. I have new slides to ring today, will issue a report once I have given one a test. Tiniest things I ever saw, dang near need a microscope to see the tip!

Your recommendation was spot on. That was the easiest batch of ringing I have done (that # of batches is pretty small though) but the paint and brush was super.

I will confess to having bought 3 bottles, just in case they disappear or get dropped from the Hobby Lobby line up, so I should be set for a while.

I don't know what I would do with a smaller brush, my eyes are crossing as I use this one and it is a 20 -no 18's in stock.

Thanks again.

Rod

[rnabholz]

Thanks for the quick reply, Kurt.. Do you also use round cover slips exclusively with ringed slides?

BillT

I don't know as much as Kurt, but as he said, the practice was started as a method to seal the coverslip to the slides. I have seen square slips sealed, but as you would guess, they follow the edge of the slip and so are not a ring.

I have seen ringing on top of a slip to denote the position of an item of interest on the slide to help the microscopist in getting in in view. This are usually pretty small circles, and as I said located somewhere on the coverslip.

Rod

[exmarine]

Ref; ringing slides.
I have six pre 1900 diatom slides and none of them are ringed, unfortunately the maker of the slides did not mention the mountant that was used, but they are perfect in every aspect.

[gekko]

Rod, this does not look like a hobby to me. It looks more like a full time job needing a lot of expertise, patience, a desire for perfection, and a delicate touch. Way beyond me. But fantastic work.

[billbillt]

Hi Rod,

"I have seen ringing on top of a slip to denote the position of an item of interest on the slide to help the microscopist in getting in in view. This are usually pretty small circles, and as I said located somewhere on the coverslip."

Leitz used to make a tool that replaced one of your objectives that would engrave a tiny circle at any point on a cover slip.. The diameter of the circle was adjustable.. I have only seen two of them for sale on Ebay, and they sold for hundreds each..

BillT

[billbillt]

Here are some pics of one of these scribers.. I was wrong about Leitz making both of them.. This one is made by Reichert..
BillT

[KurtM]

Rod, I think you'll be good with the brush you have. I can't believe how teensy these new ones are, almost too small to be practical! (eBay item number: 191772871386)

Bill, I hope Rod answered your question?

Gekko, none of this is difficult; in fact it's good clean relaxing fun. Watching TV, now that's hard. I can't do it.