Bacteria and yeast cells pictures

So I just picked up a 400X microscope from the science teacher at the school where I teach. A few weeks ago, a pro brewer told me that my brown ale was infected. So in the name of science, I figured that checking "up close" would confirm his observations or not. But I'm not sure what I'm looking for exactly. Yeast cells are obvious but how about bacteria? Anybody can help out with some shots of bacteria and yeast together to help me figure out what's going on?

It depends on the bacteria. If it is a bacillus (Lactobacillus), they will be tiny little rods at 400X. Here is a micrograph (400X) of some yeast I collected from one of my homebrews after racking from primary. The yeast, in a small amount of beer, sat for a few weeks in the refrigerator and developed the Lactobacillus infection. You can't really see them in the picture, but looking into the microscope, you could see tiny little Lactobacilli at 400X. To see bacteria better, you need oil immersion at 1000X. The bacteria are tiny compared to the yeast.

Bizoune said:

So I just picked up a 400X microscope from the science teacher at the school where I teach. A few weeks ago, a pro brewer told me that my brown ale was infected. So in the name of science, I figured that checking "up close" would confirm his observations or not. But I'm not sure what I'm looking for exactly. Yeast cells are obvious but how about bacteria? Anybody can help out with some shots of bacteria and yeast together to help me figure out what's going on?

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from my experience (from taking microbiology) seeing any cells will be a challenge without proper staining. Bacteria in general are colorless and thus not visible. I am not sure if yeast cells need to be stained but will definitely help!

At 400x it will be hard to make out most shapes as the resolution on a 400x (high-dry) will be low. I am curious what you find.. let us know!

Bacteria that you could find are Bacillus (Rod shaped), and Cocci (round). Cocci can be is pairs, tetrads, chains, and groups. There are plenty more but I suspect that is what you could see with proper staining. Good luck.

There are some drawings in Noonan's New Brewing Lager Beer.