How to Test for Bacteria on Kitchen Counters
- 1). Prepare the agar in the petri dish as directed on the package. Refrigerate upside down for the specified amount of time. You can order kits online that contain agar, petri dishes and sterile swabs.
- 2
Use a sterile swab to take your samples.ear cleaning swabs - diagonal row image by Yasen Pramatarov from Fotolia.com
Run a sterile swab over the areas of your counter most prone to collecting bacteria. Do a variety of different areas, focusing on where you most often handle your food. The edges of the sink, as well as beneath and behind items such as spice racks are great places to take swabs. Use a light touch, but make full contact with the surface. - 3). Rub the swab containing your sample on the prepared agar and close the petri dish.
- 4). Place your petri dishes in an out-of-the way spot, out of direct light. It will take three to seven days for growth to appear.
- 5). Examine your petri dishes as growth begins to appear. While determining the types of fungi and bacteria found must be left to the professionals, you can easily identify bacteria as small black spots that multiply quickly, and fungi as larger, colored, furry areas. The more spots, the higher your bacterial count.
