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Questions and Answers
What does a positive result in the catalase test indicate?
What does a positive result in the catalase test indicate?
A positive result indicates the presence of the enzyme catalase, which decomposes hydrogen peroxide into water and oxygen, resulting in gas bubbles.
Why is it important to use both positive and negative controls during the catalase test?
Why is it important to use both positive and negative controls during the catalase test?
Using controls ensures that the test results are reliable; the positive control confirms that the test works, while the negative control shows what a non-catalase producing organism looks like.
How should the slide be prepared before performing the catalase test?
How should the slide be prepared before performing the catalase test?
A drop of hydrogen peroxide should be placed on a clean microscope slide to initiate the catalase test.
What observation would indicate a negative result in the catalase test?
What observation would indicate a negative result in the catalase test?
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What bacterial species is used as a positive control in the catalase test?
What bacterial species is used as a positive control in the catalase test?
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The positive control organism used in the catalase test is ______.
The positive control organism used in the catalase test is ______.
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The reagent used in the catalase test is ______.
The reagent used in the catalase test is ______.
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A rapid appearance of sustained gas bubbles indicates a ______ result.
A rapid appearance of sustained gas bubbles indicates a ______ result.
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If no gas bubbles are produced during the catalase test, the result is considered ______.
If no gas bubbles are produced during the catalase test, the result is considered ______.
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A clean microscope slide is required to take a drop of ______ for the catalase test.
A clean microscope slide is required to take a drop of ______ for the catalase test.
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Study Notes
Catalase Test Procedure
- Purpose: Identify bacteria that produce catalase.
- Equipment: Safety cabinet, flame, dropper, pointed glass rods, microscope slide
- Materials: Hydrogen peroxide (H2O2)
- Specimens: Bacteria colonies (e.g., Sample A & B, Staphylococcus aureus, Streptococcus sps).
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Procedure:
- Place a drop of H2O2 on a clean microscope slide.
- Use an inoculating loop to transfer a bacterial colony onto the H2O2 drop.
- Observe the reaction.
- Positive Result: Rapid, sustained gas bubble formation indicates a positive catalase test.
- Negative Result: No gas bubble formation indicates a negative catalase test.
- Controls: Include a positive control (e.g., Staphylococcus aureus known to produce catalase) and a negative control (e.g., Streptococcus sps known not to produce catalase). These controls confirm the accuracy of the test results.
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Description
Explore the catalase test procedure to identify bacteria that produce catalase. This quiz covers the materials, equipment, and expected results of the test, including how to differentiate between positive and negative outcomes. Learn about the importance of controls in ensuring accurate results.