Things You'll Need
Instructions
Heat up the water so it can dissolve the NaCl more quickly and thoroughly.
Fill each petri dish with water so each dish is almost full.
Add varying amounts of NaCl to each of the petri dishes, marking each one so you can track how much NaCl is in each dish. Concentrations should be 0.5 percent, 1 percent, 1.5 percent and 2 percent. Leave one petri dish without NaCl.
Stir the solution in each petri dish until the NaCl is completely dissolved.
Wear plastic or rubber gloves to protect yourself from the bacteria.
Add equal amounts of bacteria to each petri dish.
Position the petri dishes underneath an ultraviolet lamp to provide warmth for optimal bacteria growth.
Monitor the growth of the bacteria.