You will use this for testing all isolates. You will use this to test ALL your final isolates. This special tube of red media contains a tiny inverted tube, called a Durham tube, that submerged in the media. The media contains glucose, a fairly universal sugar source for common health-related organisms. The test measures to what extent an organism can metabolism glucose.
Some organisms can metabolize glucose to acid only.
Others can metabolize it completely to carbon dioxide gas. You will use this to test ALL your final isolates. This enzyme is useful for bacteria because hydrogen peroxide is a nonspecific defense chemical we make. Thus, some bacteria can combat our defenses by neutralizing the peroxide. You will use this to test ALL your final isolates.