Test Catageory
فئة التحليل
Microbiology
Refrence Books
كتب مراجع
1. Bailey & Scott’s Diagnostic Microbiology
2. Laboratory Manual and Workbook in Microbiology
Skills Required
المهارات المطلوبة
1. Colony selection
2. Slide preparation
3. Bubble production assessment
Video Resources
مصادر فيديو
Principle
Addition of hydrogen peroxide to the bacterial sample results in rapid release of oxygen bubbles in presence of catalase enzyme. No reaction occurs in absence of catalase.
Solutions & Equipments
1. Bacterial culture plates
2. 3% hydrogen peroxide
3. Glass slides
Sample Type
Small portion of isolated bacterial colony growth from agar plate cultures.
Procedure
1. Collect small portion growth from colony with loop
2. Place on glass slide
3. Add 1-2 drops hydrogen peroxide
4. Observe slide for effervescence
Results
Bubbles—Positive result
No bubbles—Negative result
Interpretation Presence of catalase enzyme is indicated by positive test. Use along with other reactions in species characterization.
Notes:
1. Use positive and negative control slides for each new batch of stains to ensure proper staining quality and procedure.
2. Do not over-decolorize, as this can lead to false negative results.
3. Check for appropriate microscope brightness and immersion oil quality.
4. Take precautions when handling potential mycobacterial cultures.
M. Sulieman
mohammad@mlsgaate.com
The acid fast bacilli (AFB) stain is a differential stain used to detect Mycobacterium species, including Mycobacterium tuberculosis.
