Incubating (another word for 'growing')  bacteria and yeast is often a crucial part of biotechnology experiments. Like us, organisms prefer certain conditions, like temperature and humidity levels, to grow in. While some bacteria and yeast will grow if you leave them at room temperature, being able to control the environment in which they grow gives you a better chance of success and more reliable, repeatable results. After all, if the micro-organisms don't grow, you cannot complete the experiment!

To control the temperature and humidity when growing micro-organisms on petri dishes, scientists use a piece of equipment called an incubator. An incubator is an insulated enclosure where temperature, humidity—and sometimes other environmental conditions like oxygen levels—can be controlled precisely.

There are three main types of incubators: poultry or egg incubators, infant incubators, and bacteriological incubators. That's right! When babies are born prematurely or when farmers want to hatch chicks, incubators are used to keep both babies and chicken eggs in an optimal environment for them to grow and thrive. Of course, infant incubators will be more sophisticated than those you will use to grow micro-organisms, but will function under the same principles. Interestingly enough, poultry or egg incubators are sometimes used to grow micro-organisms since the temperature range to hatch eggs and grow bacteria and yeast are similar.

Now that we know what incubators are and what they are used for, let's learn to build one! Follow the video below to build a simple incubator for Petri dishes using just a thermometer, lamp, and plastic containers. It will only take a few minutes!

As this is a simple DIY incubator, we recommend that you use this incubator to do experiments where keeping the temperature constant is not extremely crucial (more on that in a moment). As you build and test this incubator, you will notice that the temperature can vary throughout the incubation period. This incubator is great for the Canvas Kit, where you can grow bacteria between 30-37℃, or the Yeast Canvas Kit, where you grow your yeast at 25-30℃ without problems. However, when it comes to experiments like the Engineer-it Kit for genetic engineering, we recommend that you use an incubator with a steady, precise temperature (like our DNA Playgrounds) or even a clean egg incubator if you have one!