In this lab activity, students

1. learn techniques for culturing bacteria using agar plates

2. design and carry out a controlled experiment to study the effectiveness of antibiotics and/or disinfectants on the growth of bacteria

Example of Student Experiment:
This lab team selected Lysol as their experimental variable.  They bravely went to the boys' bathroom and swabbed the sink handle before cleaning it with Lysol (see culture on left).  They thoroughly cleaned the handle with Lysol following the manufacturer's directions, and swabbed the sink handle, again (see culture on right).    From the cultures, one can see that cleaning with Lysol clearly had an effect on bacteria growth.   No colonies were visible in the dish on the right (after Lysol) and numerous disgusting bacteria colonies were present in the dish on the left (before Lysol).  Way to go!

Experimental (Independent)  Variable: Cleaning with Lysol
Dependent Variable: Bacteria Growth