Catalase Procedure
For The Identification of Bacteria
Catalase Test:     Click Here to View Images

The catalase test is a test for the presence of the catalase enzyme. Most
organisms posess this enzyme capable of breaking down hydrogen
peroxide.  Organisms containing the catalase enzyme will form oxygen
bubbles when exposed to hydrogen peroxide.

Tips for Success:
Do not use a nichrome loop as this will give a false-positive reaction.
Because hydrogen peroxide is unstable, always check the expiration date
on the solution. Do not perform the catalase test on blood agar, because
blood cells in the agar contain the catalase enzyme. Always run positive
and negative controls from known cultures.

  1. Place a drop of 3% hydrogen peroxide onto a clean microscope
  2. Touch an isolated colony with an inoculating loop
  3. Place the loop, carrying some of the isolate, into the drop of
    hydrogen peroxide.
  4. Observe the slide for the evolution of bubbles
  5. The reaction is positive if oxygen bubbles form rapidly.