Are cheap poratable USB microscopes good enough to count yeast, and check vitality?

Question

I have read that a 400x magnification is right for counting yeast on a hemocytometer, and also using dye to check vitality.

I'm looking at using a cheap portable $50 USB microscope. They are rated up to 800x magnification. I suspect that the advertised magnification also factors in digital zooming on these devices. Digital zooming is not magnification. They also seem to have cameras that say 3M or more with interpolation when they are actually 2M or less cameras.

Has anyone tried using these to count yeast? Would I be better of investing in a regular microscope, and buying a camera to fit it?

I will probably buy the cheap USB microscope anyway for other uses like electronics.

Answer 1

I have a little bit of experience with microbiology. If your goal is to get an accurate cell count per unit of volume you will have a difficult time. Yeast are hard to see without staining, so to do a proper count you'd have to mount and stain a slide. Bear in mind that with improper mounting technique you will end up lysing some individual yeast cells which will affect the count. Further you need a way to precisely measure a small volume of liquid (a micropipette for example).

I would strongly suggest a good ($800+) standard microscope for something like this.