Acid-Fast Stain
•Used to differentiate Mycobacteria (M. tuberculosis) from other bacteria
•Mycobacteria are lipophilic or difficult to stain.
•Once stained, Mycobacteria are resistant to counterstain.
•Nocardia are partially acid fast
•Makes use of a primary stain (Kinyoun Carbol Fuchsin), decolorizer (Acid Alcohol), and counterstain (Methylene Blue).
•Acid fast bacteria appear as bright red bacilli against a light blue background.