Science for Kids
How to Grow Bacteria in a Petri Dish
Back to Science Experiments

How to Grow Bacteria in a Petri Dish

from wikiHow - The How to Manual That You Can Edit
Ever wanted to grow bacteria for a science project or just for fun? This article will show you how to grow them in a petri dish.


  1. Buy some agar or prepared petri dishes and keep them up side down until you need them. Do not open the petri dish until you use it.
  2. Open the lid and do one of the following:
    • Press your finger against the agar jelly.
    • Place a hair in the dish.
    • Place a drop of milk or watered down yoghurt in the dish.
  3. Replace the lid quickly to avoid contamination.
  4. Tape the lid shut.
  5. Place it in a warm environment for a few days. (A window ledge facing the sun or an airing cupboard would be good places for this)


  • Keep it at 35 degrees celcius (95 fahrenheit) for optimum growth.
  • You can create comparisons by spliting the dish into sections and placing something different in each section.
  • Speak to your science teacher about disposing of the dish.


  • Never put anything in the dish which is likely to grow into dangerous bacteria (bodily fluids should never be placed on a petri dish). If the dish is reopened it could cause serious illness.
  • Never reopen the petri dish.

Related wikiHows

Article provided by wikiHow, a wiki how-to manual. Please edit this article and find author credits at the original wikiHow article on How to Grow Bacteria in a Petri Dish. All content on wikiHow can be shared under a Creative Commons license.

AddThis Social Bookmark Button
Please familiarise yourself with our Terms of Use and Disclaimer prior to downloading resources.  Contents of this website (c) Donnette E Davis and/or St Aiden's
Homeschool unless otherwise stipulated.
Join us on Twitter for Homeschool Updates, freebies, Specials and promotions