The catalase test is a useful and straightforward biochemical method for distinguishing between catalase-positive and catalase-negative bacteria based on their ability to break down hydrogen peroxide. This test is widely used in clinical microbiology and laboratory diagnostics for identifying bacterial species. Here’s a quick breakdown.
🖊️Purpose:
- Differentiate between bacteria that produce the enzyme catalase (which breaks down hydrogen peroxide into water and oxygen) and those that do not.
🖊️Procedure Recap:
- Place the bacterial sample on a glass slide or petri dish.
- Add a few drops of 3% hydrogen peroxide.
- Observe for the presence of bubbles:
- Bubbles = Catalase-positive (e.g., Staphylococcus, Micrococcus, Bacillus).
- No bubbles = Catalase-negative (e.g., Streptococcus, Enterococcus, Clostridium).
🖊️Interpretation:
- Catalase-positive result: Indicates catalase-producing bacteria like Staphylococcus and Micrococcus.
- Catalase-negative result: Indicates bacteria that do not produce catalase, such as Streptococcus or Enterococcus.
This test helps differentiate closely related organisms, such as Staphylococcus (catalase-positive) and Streptococcus (catalase-negative), making it essential in clinical settings.
