Homemade Agar


Foods 2 started with a bang making our first homemade agar to collect bacteria samples. I couldn’t believe how simple it was to make and so much cheaper than buying it. After a few youtube clips and explaining why we were doing it, I got my advanced class hooked.


Over the summer I ordered a pack of petri dishes and discovered a a frugal way to take more samples by dividing the bottom of the dish in half and labeling each section. Since the top moves, it’s not wise to write on the top unless you are taking just one sample.

We decided to make many more samples on the whim since we had so much agar. I took the suggestion of a blog and used bathroom cups and/or foil muffin cups to slip into baggies.


I used a muffin tray to hold the cups without sliding around.


The next day, we took quite a few samples in our classroom like:

  • inside of oven and microwave
  • inside of a drain
  • inside of a sink
  • classroom floor, tables, chairs, iphones, door knobs

We also went into our foyer and around school to collect samples:

  • vending machine
  • hand rails
  • public trashcan
  • water fountain
  • yes, a toilet

The sample taking was quite engaging.


Rod is swabbing his sample.


I believe students enjoyed the field trip out of class!

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