The three latest samples are clean and ready to mount. My batches never seem to get to that super white color that I have seen in the videos, remaining instead a light yellow color. Examining them under the scope in a wet mount shows that they are clean and so I am calling it good to go.
I decided to make 4 slides of just one of the samples the goal for the evening. I selected the sample from the park in Fairbank that showed such great variety.
I have found that for my intended purpose of photographing the diatoms that I prefer a sparser density to provide separation between potential subjects. My early slides were a bit dense to say the least. So to start I place a small sample taken with a pipette, trying my best to take just the top layer of the material in the tube as the denser sand had most likely settled to the bottom of the tube. It looked like this
- May24 Batch Sample.jpg (70.57 KiB) Viewed 392108 times
If I were to place that on the slide, it would be a mess of tangled and stacked diatoms everywhere. So I add distilled water to dilute the sample until it takes on a cloudy appearance.
- May24 Batch Dilution.jpg (97.19 KiB) Viewed 392108 times
Next we need cover slips. I wanted to mention a couple of things quickly. I have read references that recommend that the cover slips used be as close as possible to the .17mm thickness including the thickness of the mountant. While I have not actually done any measurements on the thickness of the mountant, I reasoned that if I selected cover slips of around .1675mm that should put me in the ball park. To that end, I took the time to measure my slips with a micrometer and sort them to the nearest .01mm. Angels dancing on the head of a pin? Maybe, but at least I can check that off of the list of potential issues.
The next tip I owe to Kurt. He told me about this little device and how it made his life easier with regard to handling cover slips, and by golly he was right. For $2 shipped from China (how do they DO that?) I got my very own Suction Pen. It really is handy when it comes to picking up slips, especially when you have cleaned them and have them ready to go. Thanks Kurt.
- May24 Batch Suction Pen.jpg (53.34 KiB) Viewed 392108 times
Four Sorted and Sized slips go on the hot plate set to about 120 F. I gently agitate the tube containing the diluted sample and draw a few drops out with a pipette and place it on a slip. The same process for the other three slips.
Next I set out four cleaned slides on my template sheet. Then grab the Pleurax, and using a toothpick place a drop on the slide over the center mark of the template.
- May24 Batch Loaded Template.jpg (43.16 KiB) Viewed 392108 times
I make a effort to make the drop a bit bigger than the last time as I had issues with covering all of the slip with a couple of slides the last time
- May24 Batch Suction Pluerax Drop.jpg (33.18 KiB) Viewed 392108 times
By now the slips are dry and the diatoms are fixed in place on the slips. Now using a tweezer, I take the slip and place it diatom side down onto the Pleurax drop, and that use the tweezer to make any adjustments to its position to center it on the template.
After all four are done, I transfer the slides one by one back to the hot plate, and turn up the heat to 350F. Once the plate reaches that temp, the Pluerax bubbles and the solvent evaporates. I give it 15 minutes at the target temp and take the off the plate to cool.
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