In Your Notebooks Determine What Quarter Of The Petri Dish

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Bacteria can be found on most surfaces, especially in the school environment. According to the NSF, a singular water fountain contains 2,700,000 colony forming units of bacteria per square inch, that’s more than an average toilet. By sharing supplies and switching classes everyday, the spread of bacteria can happen rapidly. Schools are a playground full of bacteria and through testing several surfaces, the results will show which contains the most bacteria. My original question starting this lab was will the technology have more bacteria due to how much people use them? Hypothesis: If a table, a computer keyboard, a water bottle, and a cell phone are tested, then the results will show that the cell phone has the most bacteria because of …show more content…

Note: Petri dishes are always kept with the “gel side (agar)” up. 2. Using a permanent marker, on the top (gel side), divide the petri dish into quarters and label each quarter A, B,C, D, 3. Make a label and put on the bottom of the petri dish: • Name • Date 4. With your partner, decide what four cultures you would like to study (i.e., cell phone, table top, door handle, etc) 5. In your notebooks document what quarter of the petri dish contains which culture: Example: A – door handle 6. Procedures for taking a culture: Take one cotton tipped applicator and dip into the sterile water. b. Then smear the dipped cotton tipped applicator onto the surface that you want to collect a culture from c. Gently roll the cotton tipped applicator into the gel appropriately labeled quarter of the petri dish. d. Throw the used cotton tipped applicator away e. Repeat a – d with three other surfaces. 7. Take a piece of parafilm and secure the side of the petri dish 8. Store the petri dish in the incubator Data: Day 1 Dish was spotted with slight growth of bacteria. Each section had a different type/number of bacteria: the table was a variety, the keyboard was all the same yellow dots, the cellphone has a big brown dot, and the bottle had a couple of yellow

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