Before beginning to grow your bacteria, it's important to sterilize your environment. It's important to wash your hands prior to growing your bacteria or you can contaminate your dish. Work in a clean workspace, which means clearing your workspace of unnecessary items. If you're working in a classroom, you should be provided with an already prepared Petri dish. This dish should remain in your lab's refrigerator until you're ready to use the dish. Store your dish upside down prior to use. This will prevent condensation from forming within your dish. Once you're ready to start growing your bacteria, allow the Petri dish to settle to room temperature.
Take a cotton swab and gently swab the inside of your cheek in a circular motion. Carefully open one end of your Petri dish without taking the lid off completely. According to Bacterial Growth, if you open your Petri dish completely, you risk contaminating your lid with bacteria from external sources. Take your swab and inoculate the Petri dish with your swab. It's very important to just gently streak your dish. Pressing too hard on your agar can puncture it.
Your bacteria will need a warm and quiet location. Once you've inoculated your Petri dish, put the lid back onto your dish. Take a piece of scotch tape and seal the lid onto the dish. Label your dish and store your dish upside down and away from direct sunlight. Don't store your dish next to any windows. According to Science Company, allow your bacteria to grow at 100 degrees Fahrenheit.
It can take a few days before you begin to see signs of bacterial growth in your Petri dish. It's important that during the growth of your bacteria, that you never remove the lid. Bacterial growth can be identified by several specs appearing on the agar and by a distinct, smelly odor.
Once you've completed the growth of bacteria in a Petri dish, you'll need to dispose of the dish properly. The growth of bacteria in a Petri dish creates a greater number of bacteria, which can be harmful. This means that the bacteria within your Petri dish should be destroyed. You'll need to pour some household bleach into your Petri dish prior to disposal of the dish. Be sure to use goggles and latex gloves to prevent any splattering of bleach into your eyes and onto your skin. Place your Petri dish into a sealable bag and dispose of the bag in your lab's trash bin.