microscope for beer yeast

[pdp11]

Hello,
I'm looking for a microscope that I will use to observe and analyse beer yeasts.
I'm using a toy monocular microscope, but i'm not satisfied: the condenser doesn't have iris, the structure is not stable for an 400x observation, the plate is too little and the leneses are far from planar. The sharpness il decent only at the center.
45° output is not confortable in my diy laminar flow hood.

I will use phase contrast, but not 100% of time.

I have some question: there is an image quality loss with phase contrast lens with standard brightfield?
I'll see a omax kit with 10x and 40x planar phase contrast lens? It's decent or it's better to buy an higher quality solution?
https://www.amazon.com/OMAX-Darkfield-B ... B00FG891VA
It can be mounted on a amscope t490b microscope?
The omax base microscope ‎M83EZ is to small and I think not enought though.
Or it's better to buy a serious scope as bresser infinity (with it's phase contrast kit) or an euromex IS.1153-PLPH?
Best regards,
Pe11

[75RR]

.
The phase kit you linked to plus the t490b on amazon = $800 +

For that amount of money you can get a used microscope with phase from one of the traditional manufacturers that is built to a much higher standard.

[dtsh]

Greetings pdp11,

There is some loss when using a phase objective in brightfield; I personally find it acceptable most of the time, but would switch to a different objective if what you're looking at will be very demanding for performance.

Depending on your location, you may find that a gently used instrument which has been retired from a commercial/educational setting can provide very good service for reasonable prices. I've seen a number of phase contrast instruments sell for not a whole lot more than the price of that kit, sometimes less.

(75RR beat me to it)

[pdp11]

Thank you,
I have look for on ebay (europe).
Prices for a used olympus/nikon/... full sistem are much higher... 3k€ ore more
I think that ebay is not the good place.

[pdp11]

What do you think of olympus ch40rf200?

[PeteM]

Can you fill us in on what magnification you need to easily observe (differentiate? count?) beer yeasts?

You could get clearer and sharper images, I'd think, from a 50x=60x oil immersion (500x total or even up to 600x) objective -- if a taking a few seconds to add a cover slip and a drop of immersion oil aren't too much of a hassle. In that case, both Olympus and Nikon make good and often-affordable (for the 50x) candidates.

If you want don't benefit from anything more than clear images at 400x with a "dry" objective, plus the option of phase contrast, then you might want to fit a microscope with a good plan phase contrast objective. AmScope could be OK, more established makers (with the right choice of their objectives) better. I suppose the ultimate would be a 40x plan fluor phase contrast objective. Here in the US that might mean Nikon or Olympus. If you see more Zeiss, their plan fluor objectives are excellent, if in good shape (not delaiminated). The plan fluors will be enough better in most good lines that even with the slight loss in brightfield, they'll perform very well.

[dtsh]

What do you think of olympus ch40rf200?

I'm not overly familiar with all the Olmpus models, but it is my understanding that the first character of a model represents a "class" designation. A being research, B being lab, C being educational. That said, I suspect the CH to be at least as good as the Amscope or Euromex, probably better QC and build quality. One of the things that's easy to overlook at first are the objectives; achromats are the typical default and are OK. If the objectives are plan it means the field of view is relatively flat from the center out toward the edge; the better the planarity typically the higher the cost. There are also apochromats which are better corrected for color than achromats and will deliver a sharper view, but they tend to be even more expensive. I would recommend getting plan achromats at a minimum, but I am unfamiliar with the Olympus models to make specific recommendations. The objectives with the microscope can easily alter it's value significantly making a particular example a good deal or not.

[apochronaut]

Most features on yeast are easily visible at 400- 600X and they are more easily visible in BF than a lot of other non-pigmented organisms. The benefit of phase is less evident for yeast than bacteria for instance and routine analysis of yeast performance( counts, viability, reproductive rate) can easily be accomplished with a simple 3 objective BF microscope. It really doesn't matter what the microscope is.
If one is getting down to differentiating strains in a mixed culture, then multiple tools are best used ; staining , morphology, colony size, budding features.

There may be some value in using phase to differentiate strains where cross contamination may have occured but when I did such 30 years ago, I found Bright ( negative) phase most usefull. In a pure culture the microscopy is quite simple and straightforward and one needn't agitate much over whether a microscope is capable or not. If you are on a budget buy the cheapest available.
Large breweries use DNA analysis lately.

[pdp11]

Thank you,

For counting cells i use a 40x with a widefield 10x eyepiece, blue methylene marker.
My only problem is that the field is far from flat, and i can count easly at the center but is not easy at the border to identify if the cell is alive.
For analyse cell replication I have try to use 100x lens with oil, but with my actual microscope i have no gain in detail over 40x, if I use an eyepiece camera.
The best solution is analyse direcly on the petri plate.
The biggest problem is the low contrast (no aid form methylene blue) and the thin dof.
I have done a try with oil with a 100x lens with cover glass, but the small dof and the light loss pushed me to return at 40x lens.

Olympus ch40rf200 is a lab microscope.
I will link the brochure this evening.

[pdp11]

Most features on yeast are easily visible at 400- 600X and they are more easily visible in BF than a lot of other non-pigmented organisms. The benefit of phase is less evident for yeast than bacteria for instance and routine analysis of yeast performance( counts, viability, reproductive rate) can easily be accomplished with a simple 3 objective BF microscope. It really doesn't matter what the microscope is.
If one is getting down to differentiating strains in a mixed culture, then multiple tools are best used ; staining , morphology, colony size, budding features.

There may be some value in using phase to differentiate strains where cross contamination may have occured but when I did such 30 years ago, I found Bright ( negative) phase most usefull. In a pure culture the microscopy is quite simple and straightforward and one needn't agitate much over whether a microscope is capable or not. If you are on a budget buy the cheapest available.
Large breweries use DNA analysis lately.

Thank you for your exeprience description.
I buyed an miko "toy" microscope, that do the job. 10x, 40x 100x acro lens. 1 10x eyepiece, 1 codnser without iris.
With this microscope I can count cells on a hematocytometer. But image is sharp only in the central spot. Mechanics is not good at all.
Bacteria (beer infections) are not easy to identify.
For strain separation: a shape of colony is complex to observe with my toy microscope.
I will buy somthing better. I dont need an good professional laboratory tool. But for bacteria observation I think that phase contrast is better.
And I will buy something that is good enought for keep for some years.
As I wrote in the first post, I think that my needs are a trinocular with 10x and 40x phase contrast lens.
But I will pay for a decent mechanics, better than my miko microscope.

Somthing very similar to my toy microscope:
https://www.flipkart.com/miko-plus-vd54 ... 4ce7d766ae

the olympus ch40rf200 brochure:
https://www.google.com/url?q=http://www ... db9BxWXWa9