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16 Cards in this Set
- Front
- Back
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Acid Fast staining |
- Developed in 1882 by Paul Ehrlich - Differentiates between acid fast and non acid fast bacteria |
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Genera |
Plural genus |
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Genera of bacteria that are acid fast |
1. Mycobacterium 2. Nocardia |
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Reagents used in the Ziehl-Neelsen acid fast staining method: |
1. Carbolfuchsin 2. Acid Alcohol 3. Methylene Blue |
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Carbolfuchsin |
Primary stain |
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Acid alcohol |
Decolorizer |
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Methylene Blue |
Counter stain |
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How is acid fast staining used in medicine? |
Used to diagnose tuberculosis and leprosy |
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What bacteria causes tuberculosis? |
Mycobacterium tuberculosis |
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What bacteria causes leprosy? |
Mycobacterium leprae |
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What is unique about an acid fast cell wall? |
It is made of mycolic acid, which prevents it from being stained with gram stain |
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Mycolic acid |
Unique component in cell walls Makes cell "clumpy" and "sticky" and resistant to staining |
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How does Carbolfuchsin stain acid fast bacteria? |
The heat that the cells are exposed to during the steaming process melts the lipid cell wall which allows the dye to penetrate the cells. Once the cells cool, the lipid solidifies and traps the Carbolfuchsin in the cell, which prevents it from being washed away by the decolorizer. |
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What colors are observed when using the Ziehl-Neelsen acid fast staining method and what do they indicate? |
Red (acid fast) Blue (non acid fast) |
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Procedure for the Ziehl-neelsen acid fast staining method? |
1. Cover the slide with a paper towel saturated in Carbolfuchsin 2. Steam the slide for 5 minutes 3. Let slide cool 4. Remove paper towel and rinse with water 5. Decolorize with acid- alcohol for 15 seconds and rinse with water 6. Counterstain with methylene blue for 2 minutes 7. Rinse with water and blot dry |
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What type of stain is the acid fast stain an example of? |
Differential stain |
