

![]() | Project title | Bacteria in your toothbrush![]() ![]() |
| Difficulty Level | Middle school | |
| Project page |  Click here to view this science project | |
Description | ||
| This science fair project was done to find out the best way of reducing bacteria in toothbrush. The science project experiment involved using and keeping the toothbrush in different conditions. | ||
Instructions preview | ||
| 1. For this science fair project, the independent variable is the treatment given to the toothbrush before bacteria samples are taken from it. The dependent variable is the rate of bacteria growth in the petri dish. This is determined by measuring the size of the bacteria colony using a ruler. The constants (control variables) are the room temperature, the amount of sunlight and the ingredients of the petri dish agar. 2. The 3 petri dishes prepared with agar, are stored in a refrigerator. The petri dishes are brought to room temperature before the start of the science fair project ..... | ||