Which type of stain is specifically used to identify mycobacteria?

Which type of stain is specifically used to identify mycobacteria?

• A. Gram stain
• B. Endospore stain
• C. Acid-fast stain
• D. Schaeffer-Fulton stain

Answer: (C)

The acid-fast stain is specifically designed to identify mycobacteria, which are characterized by their unique cell wall structure containing mycolic acid. This lipid-rich layer makes them resistant to traditional staining techniques such as the Gram stain, which cannot penetrate the waxy exterior of mycobacteria effectively. In the acid-fast staining method, the initial application of a carbol fuchsin dye, followed by heating, helps to penetrate the cell wall. After that, the slide is treated with an acid-alcohol solution, which decolorizes non-acid-fast bacteria while allowing mycobacteria to retain the bright red dye. This property is what makes the acid-fast stain particularly useful for identifying species such as Mycobacterium tuberculosis and Mycobacterium leprae. Other staining techniques listed, like the Gram stain, do not effectively highlight mycobacteria due to their distinctive cell wall. The endospore stain is tailored to detect bacterial endospores, and the Schaeffer-Fulton stain is another method used for endospores. Each of these techniques serves specific purposes, but only the acid-fast stain targets the unique characteristics of mycobacterial species.

The acid-fast stain is specifically designed to identify mycobacteria, which are characterized by their unique cell wall structure containing mycolic acid. This lipid-rich layer makes them resistant to traditional staining techniques such as the Gram stain, which cannot penetrate the waxy exterior of mycobacteria effectively.

In the acid-fast staining method, the initial application of a carbol fuchsin dye, followed by heating, helps to penetrate the cell wall. After that, the slide is treated with an acid-alcohol solution, which decolorizes non-acid-fast bacteria while allowing mycobacteria to retain the bright red dye. This property is what makes the acid-fast stain particularly useful for identifying species such as Mycobacterium tuberculosis and Mycobacterium leprae.

Other staining techniques listed, like the Gram stain, do not effectively highlight mycobacteria due to their distinctive cell wall. The endospore stain is tailored to detect bacterial endospores, and the Schaeffer-Fulton stain is another method used for endospores. Each of these techniques serves specific purposes, but only the acid-fast stain targets the unique characteristics of mycobacterial species.