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Unformatted text preview: Non Acid-fast Primary Stain Carbol fuchsin 5 min Fuchsia Fuchsia Decolorize Acid alcohol <30 sec Fuchsia Colorless Counterstain Methylene Blue 30 sec Fuchsia Blue ii. Kinyoun Method 1. uses a wetting agent (detergent) with the primary stain to soften mycolic acids, allowing the stain to enter e. Critical issues i. Decolorization: too much or too little will give false results ii. Age of cultures: older cells (>24 hours) are crucial as younger cells have lower proportion of mycolic acids in the cell wall iii. Dense smear: decolorizer cannot penetrate and will see mixed results iv. Always use control strains when working with unknown cultures f. Procedure i. Each student will complete two acid fast stains according to the Ziehl-Neelson Method. The organisms that will be acid fast stained are Mycobacterium sp. (#16) and Staphylococcus aureus (#6)....
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- Fall '08