The Catalase test

The Catalase Test is used to detect whether or not an unknown bacterium has the enzyme, catalase. All members of the genus Staphylococcus have the catalase enzyme. The catalase test is the differential test between the genera Staphylococcus and Streptococcus.

To perform the test, transfer a colony of the unknown bacteria to a clean microscope slide and add a drop of hydrogen peroxide to the bacteria.

• If bubbles are immediately seen on the slide, the catalase test is positive.
• If no bubbles are immediately seen on the slide, the catalase test is negative.

The reaction is summarized in the equation below:

2 H2O2 ------------------------> 2 H2O and O2 (bubbles