How to Use a Glass Petri Dish
- 1). Mix agar and water in a small bowl according to the directions on the agar container. It will have a gelatinous consistency. Pour the mixture into the bottom of the petri dish so that it forms a very thin layer. Place the lid on the dish immediately.
- 2). Moisten the tip of a cotton swab with distilled water. Use the swab to collect a bacteria sample. You can swab a door handle, furniture, windows or any other dry surfaces exposed to germs and bacteria. If you want to use a saliva sample, you do not need to moisten the swab.
- 3). Remove the lid from the dish. Gently wipe the cotton tip across the surface of the agar. Replace the lid immediately.
- 4). Move dish into a warm temperature for efficient growth, 70 to 95 degrees.
- 5). Watch for cultures to form in four to six days.
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