Cheap microscope for yeast counting

[jhsbaker]

I am looking at getting a 400x microscope for yeast cell counting. Prices range from about $50 for a cheap USB microscope to well over $1000. Has anybody got a cheap microscope that does the job for counting yeast cells?

 

[klangers]

I haven't heard of anyone using a microscope to count yeast. Maybe there are people that do it (outside of labs) but I haven't heard.

The problem is that in order to see anything at that level you're going to have to invest in optical-quality petri dishes and smear the yeast on them real thin as you need a backlight in order to see the cells. I'm not sure how useful this would be at getting an accurate cell count (well, more accurate than other "macro" methods).

I do a bit of photography and one thing I've learnt is that cheap "optical" glass is rubbish. A decent microscope (ie capable of 400x without hideous aberrations or distortions) is going to cost a decent sum of money; there's no way around it.

Apologies if you already know this, but it just sounds like overkill to me and I want to make sure you're aware of the (potential) can of worms you may inadvertently open for yourself.

 

[jhsbaker]

Thanks for feedback klangers.

The yeast counting slides are not expensive (< $20), and have squares on them to help with counting the number of cells/unit volume. I was hoping that just for the purpose of counting the number of cells a bit of distortion would be acceptable. I don't want to end up spending a bunch of cash for something of questionable benefit to my brewing operations, but I would like to have some degree of accuracy in estimating how much yeast I'm pitching.

Regards
James

 

[verysupple]

I haven't heard of anyone using a microscope to count yeast. Maybe there are people that do it (outside of labs) but I haven't heard.

The problem is that in order to see anything at that level you're going to have to invest in optical-quality petri dishes and smear the yeast on them real thin as you need a backlight in order to see the cells. I'm not sure how useful this would be at getting an accurate cell count (well, more accurate than other "macro" methods).

I do a bit of photography and one thing I've learnt is that cheap "optical" glass is rubbish. A decent microscope (ie capable of 400x without hideous aberrations or distortions) is going to cost a decent sum of money; there's no way around it.

Apologies if you already know this, but it just sounds like overkill to me and I want to make sure you're aware of the (potential) can of worms you may inadvertently open for yourself.

I have a microscope and occasionally bother counting cells.

Firstly, you don't use a petri dish for counting. How would you know what the volume of liquid you were conting cells in was? You use a haemocytometer which has a grid on it and a gap between it and the cover slide of a very specific thickness so the volume of liquid covering a given grid square is known.

Secondly, 400x magnification is bugger all. Even cheap student quality microscopes (admittedly still a few hundred dollars) with their standard objectives and eye pieces will give you a nice crisp image at that magnification. You'll struggle at about 1000x, though, as then you're getting into the range where you need oil immersion. But unless you want to get a close up of some bacterial contamination you won't need that.

Unfortunately I can't help th OP about what type or where to get a microscope that's suitable as I got mine for free (the uni was going to throw away a bunch of the old style ones with a mirror instead of a lamp). It's a bit over kill for yeast counting. I have objectives and eye pieces allowing up to 1250x but I struggle to get enough light using the mirror at those magnifications.

The one thing I can help with is that you should get one with a mechanical stage. It's almost impossible to move the haemocytometer the tiny amounts needed for accurate counting by hand.

 

[klangers]

I stand corrected!

 

[AzzA68]

I bought a SEM a few years back, it set us back US$205k... but the exchange rate was favourably about 1.08˜1.10 at the time... very good for measuring the cell dimensions and finding cells with nodules/buds (where they separate to multipy). Of course the cells are very much dead, having been protien fixed (so they don't deform under very high vacuum), soaked in ethanol, put through a Critical Point Dryier, and sputter coated with about 25nm of gold/paladium, so they're not much use for brewing with anymore. We can get a full screen image of a single yeast cell though.

 

[dent]

What I find more useful is the ability to check the yeast viability - for instance, I had a batch of some english ale sitting in the fermenter, cold, for two weeks after it had fermented out. After kegging it, I checked the yeast in the trub - it was down to 30% viability!

 

[altone]

Unfortunately I can't help th OP about what type or where to get a microscope that's suitable as I got mine for free (the uni was going to throw away a bunch of the old style ones with a mirror instead of a lamp). It's a bit over kill for yeast counting. I have objectives and eye pieces allowing up to 1250x but I struggle to get enough light using the mirror at those magnifications.

Have you tried training a few high output LED's at that mirror?

They only cost a few bucks, I use them now instead of photo lights in my lightbox.
(I still do a bit of product photography to keep the sherrif's from the door)

 

[mombius hibachi]

While $400 isn't "cheap", I have one of these and works a treat.

http://www.ebay.com.au/itm/Seben-SBX-5-Stereo-Lab-Microscope-6-eyepieces-2000x-/380284548957?pt=AU_Business_Industrial_Medical_Scientific_Equipment2&hash=item588ab9b75d

I figured I could spend $100 on something that may be a piece of crap or spend a bit more and get something reasonable.
I use it regularly as I live in the country and have sketchy access to fresh yeast.
I got sick of brewing "blind" having no real idea how much yeast I was pitching and what was causing variation in brews, it's good to know what's going on.

 

[AzzA68]

That Seben SBX-5 Microscope, on ebay, is almost identical to the 20-odd year old high-end "whateverbranditis" that we have in one of our labs, except ours has a camera port and probably cost thou$ands. Some of the kiddies were using it the other day to photograph yeast cultures (being used for pharmacuticals not beer, but the truth is they're not that dissimilar... be it candida or cerveza... the cells are not that much different in shape or size).

 

[brewermp]

I read this post wondering why someone would want to count yeast lol.

 

[Yob]

I bought a SEM a few years back, it set us back US$205k... but the exchange rate was favourably about 1.08˜1.10 at the time... very good for measuring the cell dimensions and finding cells with nodules/buds (where they separate to multipy). Of course the cells are very much dead, having been protien fixed (so they don't deform under very high vacuum), soaked in ethanol, put through a Critical Point Dryier, and sputter coated with about 25nm of gold/paladium, so they're not much use for brewing with anymore. We can get a full screen image of a single yeast cell though.

gosh

 

[verysupple]

What I find more useful is the ability to check the yeast viability - for instance, I had a batch of some english ale sitting in the fermenter, cold, for two weeks after it had fermented out. After kegging it, I checked the yeast in the trub - it was down to 30% viability!

How did you test the viability? I've used methylene blue but that's not very accurate below about 90 %.

Have you tried training a few high output LED's at that mirror?

They only cost a few bucks, I use them now instead of photo lights in my lightbox.
(I still do a bit of product photography to keep the sherrif's from the door)

That might help a bit, but you really need parallel light for the mirror to work effectively. I get plenty of light for work with yeast anyway. It's only if I go way up on the mag (above ~1000x) that I need more light.

 

[welly2]

This belongs here

You know you are hooked when...

...you're counting yeast cells.