MicrobeHunter.com Microscopy Forum

Used (but classic) B&L 3L abbe refractometers come on sale on eBay for widely variable prices. Liquid refractive index can be measured from a single drop, and it's possible to measure RI for some solids (like dried mounting medium on a coverslip), too. The 3L is pretty easy to work on / repair (it t...

I watched the owner's video and honestly, for this specimen, I don't feel the need to use an objective with a NA over 1.0 .... As for the color, the difference between the APO objective and the Splan objective can only be seen when taking photos. So, the gain is almost nothing compared to the troub...

To my eye, the tungsten halogen is vastly better than either of the LEDs. You are getting a lot of green or purple CA from both of the LEDs, and it is obscuring detail.

A cheaper LED might have a lot of blue in its spectrum which could exaggerate the perceived CA. On the other hand running a 12v bulb at 6v is going to give a pretty far from neutral spectrum too I'd think. No, it's not an excess of blue that's the issue in my experience. I say that because you can'...

I was thinking as I read through the series of posts that your LED and not the DSLR is probably a major culprit here. They often have been for me...

Aren't inverted microscopes typically made to use ELWD objectives, for looking through the bottoms of petri dishes and flasks? . . . . Does this mean you can use non ELWD objectives and just flip the slide over? Yes, that is what it means. It's nice if you can fit a high NA condenser that will rack...

I can always change up but once the oil has been added, yes it can be removed but it is very difficult to maintain registration with a fresh mount. This raises a good point. My microscope is inverted. It's simple to add oil to the oil objective as long as I remove the slide holder area of the stage...

I'm going to need to build an LED illumination setup shortly. Probably this will be based around a 10W COB but the lamp may be as high as 20W. What are folks using for their PWM dimmers on DIY LED lighting systems these days? Digital camera banding is of course a concern. The cheapo 8 amp PWM units ...

Thanks!! Leonard

I know more about rose galls than oak galls, but I think a start on answering your question has to begin with: When and how does your green parasitoid(?) inquiline(?) colonize the oak gall and/or the Cynipid larvae inside of it? Once you know that you can maybe start to look for behaviors at the app...

Very nice. Is the green parasitoid an Ormyrus of some kind?

These people may be selling them from China?

http://www.ningbomicroscope.com/ensite/ ... _1285.html

Skeptical, but interested.

Acrylic is depolarizing the light, then.

Interesting. Petri dish functioning as wave retarder? I guess. Did you set it up for true darkfield before adding the polarizers? Am thinking probably not, that this must be oblique lighting and not true DF. What happens when you turn the polarizers slightly away from the extinction point?

"I have used ebony-coloured polyurethane wood varnish with some success on slides of paper fibres mounted in 99% glycerol. Glycerol is not really a permanent mountant so I needed something to seal it." Polyurethane varnish is a really good thought! I think many polyurethanes bond very well to glass,...

Excellent! As long as the Nikon S's fine focus gears don't break (the very early ones, before they started calling it the Model S, had brass gears), they're really very nice instruments, especially the lighting system. I especially appreciated the phase annulus centering mechanism that Nikon used - ...

There is no aperture coupling to the camera on the PFM (and certainly not an electronic coupling!), so the most bare-bones F mount to E mount adapter should do the trick. If the shutter on your PFM still works, you will probably get better stability setting the Sony (Alpha?) shutter to "B"ulb and co...

Glyptal, typically. If there is going to be a call to use solvents to clean the slide at some point, I give the exterior layers of Glyptal a coating with gum arabic over the top. Quick dry nail polish if drying speed is important, or to "tack" the coverslip down. Much depends on what your mounting m...

For the samples, I really like 20ml glass scintillation vials, the kind with the plastic poly seal cone for the cap (not the foil pad.) Wheaton 986586, for example. There are others. You can find them surplus for cheap quite frequently. Write identifying details in pencil on a slip of plain white pa...

It's a piece of birefringent material that shifts the polarization state of light and "retards" the extraordinary ray a specified fraction or multiple of a wavelength (at a specified wavelength - for microscopy, usually green). The phase shift results in cancellation of some wavelengths when the two...

If the large structures in your photo are just starch granules, then yes a pair of polarizers will show them when crossed as birefringent disks with a maltese cross interference pattern. If you can lay hands on a first order compensator (even a plastic one), you'll get some pretty interference color...

First off, wow, cool, congratulations! Second I am not sure, but that looks like a freezing specimen platform, in which case the white "knob" as probably a port for introducing liquid CO2. The black one might be a valve? Third I think I might have a big Lipshaw knife - if you're interested, let me k...

Never worked with yeast or looked into this, so just a couple of guesses - First, are you sure everything imaged is yeast? Could any of it be flour or starch granules from the flour? Second, my guess would be that if only some yeast are staining in the Lugol's, they are dead. It may be that the Lugo...

Ah, good! I see there are a number of sellers in China offering a set of 20 of the fishbone version on eBay at $12 and change right now. I am definitely going to give your thumbscrew idea a try, but I think the two boards just might end up working better. I do know that getting the pressure just rig...

Hi, Pete. The ones you have there aren't the fishbone type, from what I can see, but another similar configuration that are made by the same factory and often sold in sets with the fishbone variety. They don't work as well as the fishbone shape because the clamping surface is larger on the ones you ...

Hi again. Haven't used the procedure with PEG in water as mentioned in the post you reference. I do have substantial experience with Steedman's wax, though (that is, PEG 400 distearate and cetyl alcohol flakes mixed at 9:1). I can tell you that the biggest problems with Steedman's wax (and perhaps a...

No, I think Toluidine Blue-O has been around a long time - 1850s or so. I looked in my copy of Gray's formulary from 1954, and he lists formulations from at least 1905, and probably before. Didn't do an exhaustive search. Lugol's iodine is one of the oldest stains used in microscopy, and one of the ...

I agree with John's comments above. Alcian Blue 8G will indeed work quite well with Safranin-O. It's also a very good counterstain for Nuclear Fast Red, so a good one to have in your arsenal. But Fast Green is the way to go if you can find it. I haven't tried Light Green in this application, so I ca...

Try buying it flowers?

For botanical work with safranin, definitely lay hands on Fast Green FCF if you can, and prepare it in 100% alcohol (ETOH or IPA); use it as the counterstain to your aqueous safranin. You should be fine with the safranin at 0.1% for most botanical work. They key to using safranin well is timing how ...