How can I tell if my microorganisms are alive or not?

[deleted-356182]

I'm doing a project that requires me to grow microorganisms. I ordered fungi, amoeba, paramecium, E.coli and Bacillus. But then I wasn't able to culture them for about 5 days. How do I know for certain that the microorganisms aren't dead yet?

[SciB]

The best way to find out if the amoeba and paramecium are alive is to look at them under the microscope and see them moving. The E coli and Bacillus you can spread on nutrient agar in a Petri dish and see if they form colonies. By 'fungi' I assume you mean some kind of yeast. These also you could look at under the scope, but if you give them some sugar and they make carbon dioxide then you know they are alive.

All of these organisms should survive for weeks as long as they are in the liquid medium in which you received them. If you want more information on their growth and survival call the company you bought the organisms from and ask them. I usually refrigerate bacteria and yeast that I am working with but I don't know about amoebas and paramecium. Keeping the cultures at 4 degrees C is a common way of preserving them. Again, ask the company for their advice on keeping your microorganisms happy.

Sybee