Catalase is an enzyme prezent in most of the organisms and is involved in decomposition of the hydrogen peroxyde
in H2O and O2. Some bacteria can not produce catalase so, in bacteriology this test is used together with other tests
for bacteria identification.
Prepare a 3% hydrogen peroxide solution and put 1 drop on a slide.
Harvest a well isolated colony and immerse the loop in the solution on the
Observe the quick effervescence for a positive reaction. The absence of
bubbling is considered negative.
As an example, generally Staphylococcus species are catalase positive
and Streptococcus species are catalase negative.
Use culture grown on a blood free media. Erythrocytes may produce a false positive reaction.
Using a nichrome loop may give a false-positive reaction.
Reaction is more intense when adding on the slide a drop of commercial soap solution before the hydrogen peroxide.
(c) Costin Stoica