How do you determine bacterial growth in petri dishes?

Question

My 11 yr old is doing science proj. Lots of growth. Swabed dog & human in seperate dishes. How do we determine what it is? HELP needed ASAP!! Thanks

Answer 1

Bacteria are usually found in colonies. They rarely occur singly. You can detect bacterial growths in the plates therefore by the formation of this colonies. Fungi do have hyphae or projections so you can easily identify contaminants from your culture.

Answer 2

Well its a complex job, u can do couple of things

1. Look at the nature of the colonies thats grown in the dishes, like color, smell

2. u can stain the bacteria taking out of its colony, it might not be only bacteria, could be fungus too... however viruses are not grown easily

3. u can perform certain tests(better done by the microbiologist though)

4. at home, u can check it out if u have microscopes and stains otherwise ur microbiologist fren could help u if u have one.