How do you grow bacteria using a petri dish?

Answer 1

To grow bacteria on a petri dish, you will need several items.

First you will need a petri dish with lid. The petri dish must contain agar, which is the source of the nutrients for the bacteria you want to grow.

Then you will need sterile cotton tipped applicators. They must be sterile so that the bacteria you put in your dish is the only bacteria there, and not extra from an exposed cotton swab. There are also other laboratory tools that can be sterilized to pick up bacteria with.

Then you need your source of bacteria.

When you know what type of surface you will be swabbing, isolate one area, and swab it thoroughly with the cotton tipped applicator. Then, immediately swab it gently onto the agar surface with a back and forth motion.

If testing two different specimens with one petri dish, be sure to only swab half of each side with each specimen. On the bottom of the dish, use a marker to note which side contains which sample.

After preparing your petri dishes, place the lid on them and be sure they are labeled for easy identification. Then your specimens need to be incubated. Different types of bacteria thrive better at different levels of incubation and time. See a laboratory manual for incubation times.