MicrobeHunter.com Microscopy Forum

Thanks MicroBob for the additional info and the idea of shellac glue for the diatoms. I will check where I can get shellac flakes. Silicon glues contain organic solvents and are probably attacked by essential oil, so I think that for sealing, I prefer gel nail polish. If that fails on the long-term ...

Hi MicroBob - thanks for the post and for the very important remarks. I already attempted to lower the density of the diatoms on the slide, to obtain a "monolayer". However, your point, that a less dense layer will also improve the photo quality is great!! And many thanks for the link about how to m...

Very Beautiful. Thanks.
Would be nice to know some details - objective, illumination type, light (any filter?) , which camera....

PeterM Firstly, your way of leading youngsters into science is admirable. To the point - if the child is familiar with trigonometry, he can learn the math of wave motion. And the physics of microscopy stems from wave behaviour as well as simple ray tracing and ray geometry. Then by learning the idea...

P.S.: I somehow forgot to mention that when mounting diatoms, the drop of PS-CBO should be small, such that spreading under the weight on top of the coverslip will still leave some space under the coverslip. So, the medium will not be in direct contact with nail polish. This is because, as I mention...

zzffnn - thanks for the links. Michael - Thanks for the post. I did not read the link about polystyrene and toluene. They possibly removed all of the toluene, without due press on the coverslip, so the solvent vapors escaped too rapidly for the PS residue to establish itself in the space between the...

Martin I had a similar problem with Olympus objectives. On ebay you can find parfocality adapters from China as well as from Europe. Very inexpensive, relative to the original adapters from the microscope manufacturer, and they offer a range of parfocality corrections (like 8mm, 9mm etc). But better...

zzffnn - I would really post better photos if I could. I have carefully read your posts about the glass bond from HOBBY LOBBY in other your threads. Looks like I should try it or a similar glass bond from crafts stores, at least for sealing around the coverslip, instead of nail polish. Who knows, it...

zzffnn, One thought that crossed my mind is how is any adhesive fit for mounting. Supposing that the diatoms are lying flat on the slide. If you heat the slide to such high temerature that they partially melt and "welded" to the slide - forming a "glass bridge" - then after cooling you can use any a...

Hobbyst46, Nice work, thank you for sharing. I assume you do not have a refractometer? If the medium's RI is 1.55-1.6, then it may be useful for most diatomists, except for those who do dotting on Frustulia rhomboides or Amphipleura pellucida. Uncontrolled random strews without comparison may not p...

For diatoms, a high refractive index (RI) mounting medium is wanted. Commercial resins or solutions of RI 1.6-1.7+ are expensive, or hard-to-get, or have a limited shelf-life, or contain toxic solvents like toluene. Looking for a more "domestic" stuff, I conceived a (apparently new!) mounting formul...

Martin, On some Zeiss and Olympus microscopes the condenser rack has an upper "stopper". That is to say, when the condenser rack is not installed on the microscope, the vertical movement range is wider - centimeters, not millimeters. And you can raise it so it is higher than the stage itself. Howeve...

Beautiful!!
They do not move fast. Did you add something, like methyl cellulose, to slow them down?

Thanks 75RR for the emphasis, I fully accept. Progressing step by step, now to improve the photo-micrography skills. Some diatom photos are due to be shown on the slide and specimen forum.

I am not familiar with Accuscope but, in my humble opinion, the "problem" is not with the original light source. Halogen lamps are still standard light sources on premium research metallurgical microscopes. I WOULD NOT replace it with a LED just because of the present issue. I agree with zzffnn abou...

Thanks, BillT and Kurt for the encouraging replies. Kurt - seen your microscope collection presentation in the second link. Very impressive demonstration that fine microscopy is mostly based on the love and proper care of the instrument. RetroDiode is on the site www.retrodiode.com. I agree that neu...

Sorry - photo was too large...
now added 2 photos

I thought I should share my experience in this forum. I purchased my old used ZEISS GFL, which is a great little microscope, but decided to replace the original 6V, 15W tungsten-lamp power with a more modern and reliable illumination setup. Various home-made LED upgrades have been described. The ele...

Hi Rudi Diatom separation is apoarently a tough mission that challenges geologists, paleontologists and other researchers. There us a sophisticated method acronymed SPLITT. It is a separation of diatoms from other stuff by means of selective sedimentation or flotation in a laminar water flow. The ch...

Hi Peytr One liquid that is not a "harmful chemical" by definition is Cinnamon bark oil. It has a refractive index of about 1.55 and to my eyes appears to be a good mountant for diatoms. It is available from natural products stores/suppliers. So the price is not prohibitive and it is freely marketed...

(Continued) - Sorry about that typo - Wait an hour, not weight an hour...

From my humble experience with diatoms on the one hand, and some acquaintence with diatom cleaning methods in research as described in the literature, as well as with chemicals, may I suggest avoiding H2SO4 (sulphuric acid) at ANY home laboratory. H2SO4 is a strong oxidant. Even more so when hot. Bu...

Thanks Charles, Yes, I found the long forum thread initialized in 2015 by markG, and your very helpful remarks. His condenser rack was apparently much worse than mine. Otherwise, his challenges and doubts of that time appear familiar to me now. I must preserve this condenser for the GFL with great c...

Hello again. Mike - sorry I forgot to answer your question, but yes, my condenser rack for the Zeiss GFL carries three holders: The top is the original auxiliary lens, the middle is a filter holder and the bottom one is a similar auxiliary lens salvaged from a spare, unused rack. I find that using t...

Mike - indeed, the major problem was dirt and dried grease around the brass disk under the condenser top plate. I cleaned it carefully with a minimum of light petrol, which improved the phase allignment tremendously. Regarding the condenser rack, I loosened the counter-screw (the one that is coaxial...

Mike - many many thanks!!!

Yes, the lever ("knob") is lockable and functions OK. Only the other level ("knurled disk/ring") is troublesome. I will try and follow your advice.

Thanks photomicro, here are some photos. The base is round, the substage plate is removable, no model name is inscribed on it so I thought it was GFL... I have upgraded the condenser rack by adding a third filter/lens holder (from a spare condenser rack), but this change is not related to the proble...

Hello I would appreciate an advice for maintenance of a phase contrast Zeiss condenser, Achromat-Aplanat model Z III 6 (or similar) for an old but usable Zeiss W GFL microscope. It has the following positions: brightfield, darkfield, (missing) DIC prisms, Ph2 and Ph3. There are three separate proble...