

![]() | Project title | Concentration of disinfectant and survivability of bacteria![]() ![]() |
| Difficulty Level | Middle school | |
| Project page |  Click here to view this science project | |
Description | ||
| The purpose of this experiment is to determine the relationship between the concentration of disinfectant and its effectiveness in destroying bacteria. | ||
Instructions preview | ||
| 1. The independent variable of this experiment is the concentration of disinfectant used, which is 10%, 20%, 30%, 40% and 50% respectively. The dependent variable is the diameter of the zone of inhibition formed around the bacteria culture. The constants in this experiment include using the same type of bacteria, type of disinfectant, temperature of incubator and incubation time. 2. Prepare a sterile area in the science laboratory Wipe the work table’s surface area and all the materials with alcohol soaked wipes. Do not wipe the nutrient culture or open the cover of the Petri dish. Leave the bacteria ..... | ||