Which microscope to buy??

[nealperkins]

So, I bought one microscope and it is fine for counting yeast cells but I would like to be able to spot bacteria. What recommendations do the knowledgeable people have on this?

...and is there a good place to acquire such a thing?

Thank you!

 

[adrock430]

Oil immersion is your best bet, especially if you stained...

 

[butterpants]

There's a thread I started in brewing science that has a few folks who chime in on microscope selection. You'll need at least 1000x and phase contrast to really play with bugs. They get expensive fast.

 

[OakPond]

The big question here is price range.

 

[nealperkins]

Thanks for that info. I may get 'priced out' but I think I'll give it a shot.

Anyone know of good sources to start with?

Thanks

 

[trentm]

So, I bought one microscope and it is fine for counting yeast cells but I would like to be able to spot bacteria. What recommendations do the knowledgeable people have on this?

...and is there a good place to acquire such a thing?

Thank you!

Are you really sure you want to be able to observe bacteria? For contamination, once the levels are high enough to find them by microscopy, it's way too late and visual identification of species is very limited. I don't think you could count them for pitching purposes. And there is not much to be seen with even a high end light microscope.

 

[nealperkins]

Hmm, Thank you for that post! Perhaps I don't really need a better microscope. I have one that is quite sufficient for yeast cells..

And, I will shortly experiment with the washing technique using chlorine dioxide.

Let me ask another question...

Occasionally, I intend to use some washed, stored yeast for another starter and pitch and find a nice little colony floating on the surface of the water. I have always assumed it was all bad and threw it all out (even though the yeast slurry itself smelled fine).

Now I wonder if I could salvage the yeast, especially with the chlorine dioxide treatment before the starter.

Any thoughts about that?

 

[GreyEagle]

In order to correctly identify species and type (gram positive, gram negative) you would also need a gram stain-stain kit. Even with the kit you would be hard pressed to identify the bacteria without an ID analyzer seen in most microbiology labs. A basic scope, such as an Olympus that I use in my lab would be fine. You would need an oil immersion lens (100x and/or 50x) as well.
I would have to ask what is your goal? Observing bacteria without staining is purely semi-quantitative. Bacteria also stain differently when direct staining (staining dried drop of beer), versus staining colonies from culture.
Sorry if this is confusing. Message me if you need more info. I have access to the microbiology lab in the hospital I work at.

 

[deeringbrewing]

What magnification are you using now?
I'm not trained but do have a scope and have been looking.
Hears some bacteria that contaminated a dish around the outer edge. Easy to see at 400 times. These picks were taken with an ipad held by hand so they are not the best. My glass is a little old so it has some marks that can be seen in the image, with the eye the rods are very easy to see.

Yeast cells with a little bacteria about.

Hears a sample after a 24 hr soak in starsan to see if it killed all the bacteria and to see how the yeast handled the soak. Notice all the budding I didn't realize they multiple bud. The soak greatly reduced the bacteria but there may still be some. I'm letting the culture sit to see if the bacteria come back. Just an experiment.

I'm wondering why the concern with identifying bacteria. Does it matter? If you see any? One is bad right? Unless you are using yeast/bacteria fermentation, then you may need to identify the imposters?

I'm running some trials with streaking on agar to get a clean strain and culturing up to pitching size with sterilized wart. Checking for infection along they way. Been collecting some expired packs of the local brewers to play with. They all seem to have viable yeast in them.
Hears the plate with the bacterial around the periphery of the culture. These were the rods in the first pick.

Again I'm just observing some things not an expert or anything....

 

[trentm]

Hmm, Thank you for that post! Perhaps I don't really need a better microscope. I have one that is quite sufficient for yeast cells..

And, I will shortly experiment with the washing technique using chlorine dioxide.

Let me ask another question...

Occasionally, I intend to use some washed, stored yeast for another starter and pitch and find a nice little colony floating on the surface of the water. I have always assumed it was all bad and threw it all out (even though the yeast slurry itself smelled fine).

Now I wonder if I could salvage the yeast, especially with the chlorine dioxide treatment before the starter.

Any thoughts about that?

Sorry, I have no experience in washing yeast, however, I am interested in your chlorine dioxide treatment. I have heard it works great.

 

[deeringbrewing]

What magnification are you using now and what are the benefits in identifying the bacteria? You don't want any right?

 

[WoodlandBrew]

+1 to phase contrast if it is in your budget.

Amscope makes a reasonably priced scope with a 100x oil immersion objective. (The resolution is fine as long as your slide cover is the correct thickness)
http://www.woodlandbrew.com/2012/11/amscope-binocular-compound-microscope.html

An alternative to washing with chlorine dioxide is acid washing with star san:
http://www.woodlandbrew.com/2013/03/acid-washing.html

 

[nealperkins]

Well I've forgotten how to post pictures. But the objective lens are marked 4, 10, 40, and 100. The replaceable eyepieces are marked P16X and WF10X/18.
I certainly have no issues with counting yeast and the staining issue.

I think I am learning here that for bacteria, I was trying to do the wrong thing. Perhaps the right thing is to assume that all stored yeast is contaminated and wash it prior to making the starter?

Very interesting regarding the Starsan wash! (BTW, just bought the book) I am going to try this very shortly dividing a contaminated container of yeast. As an aside, I wonder how contaminated the slurry is as the infection is floating on top of the water (I did not completely top off the mason jar with water...)

I hope work in this area will continue as it is a big deal for those of us who brew often!

 

[WoodlandBrew]

Perhaps the right thing is to assume that all stored yeast is contaminated and wash it prior to making the starter?!

That sounds like a reasonable approach. You'll find details on acid washing in the book on pages 120-125. Acid washing is hard on the yeast, so you are smart to wash right before pitching.