Christine Case, Skyline College

Handwashing. Which quadrant do you predict will have the most bacteria? Scroll over the numbers to interpret these data.

plates

Each circular growth is called a colony. A colony results from growth of a single cell (or group of cells, colony-forming unit).

Control. No washing

After first washing with water.

After third washing with water.

After first soap + water wash.

After fourth soap + water wash.