First bacterial culture

[Lilly Begonia]

I cultured these in one of my new petri dishes two days ago and I'm thinking they are some kind of bacilli. There are small round bacteria too, moving around in there.



Elsewhere on the slide these were stained with methylene blue.

[Pat Thielen]

There you go!
I just found this thread after I responded to an earlier post (so you can probably ignore that one).

[Jonnyvine]

Good job!

You said you grew them yourself. Is it possible to tell me what you did to grow them?

[Lilly Begonia]

Good job!

You said you grew them yourself. Is it possible to tell me what you did to grow them?

Well I bought some petri dishes on Amazon that had the nutrient agar already in them, then used a cotton swab to smear what I wanted to culture across the agar. The cultures expressed themselves in a couple days.

[Crusty]

Before I retired I was an epidemiologist at the infectious disease bureau of the NYC Department of Health, which is why I am concerned. Nothing could make me play with bacteria without strict sterilization protocols. How do you handle the less photogenic aspects of bacteria?

[zzffnn]

Before I retired I was an epidemiologist at the infectious disease bureau of the NYC Department of Health, which is why I am concerned. Nothing could make me play with bacteria without strict sterilization protocols. How do you handle the less photogenic aspects of bacteria?

Bacteriologist here and I agree 100%. I suggested baker's yeast to Lilly Begonia before, as an alternative, but (s)he did not seem to consider that suggestion. I respect that decision though.

[Lilly Begonia]

I note it doesn't seem to matter WHAT I cultured. Hint: It wasn't yersenia pestis. But I'm not even asked. Moving right along....

[zzffnn]

I note it doesn't seem to matter WHAT I cultured. Hint: It wasn't anything infectious. But I'm not even asked. Moving right along....

Do you know exactly what strains you cultured or have there, are you really sure that they were not infectious (how did you know there was no contamination or mutation)? Did you start from a single colony of pure bacterial strain and transfer it near open flame, with alcohol cleaned tools and gloves?

Bacteriologists usually start culture with a single colony of a known strain, and operate near flame to avoid contamination of other bacteria. After culturing, they usually do specific staining/test or gene sequencing to confirm they are the exact same strain (not mutated or contaminated during culture).

Some times, even for the same species of bacterium, a daughter strain can quickly obtain or mutate a gene and become virulent, even though starter strain is not virulent.

Edit: To produce pure bacterial culture in a lab, scientist usually adds antibiotics in culture media to kill all other (contaminant or mutant) bacteria, except for the strain desired. Such desired strain is given antibiotic resistant genes by genetic engineering, prior to culture. Why bother with so many steps? Because if you don't do that, you wouldn't easily tell what bacteria you have there.

It was for your own safety, that we suggested not to culture bacteria. At least, I won't want to culture bacteria at home, even though I was a bacteriologist by trade.