Ziehl-Neelsen technique

Definition

The Ziehl-Neelsen technique is a staining method used to identify acid-fast bacteria, particularly Mycobacterium species. This technique involves the application of carbol fuchsin dye, heating, decolorizing with acid-alcohol, and counterstaining with methylene blue.

5 Must Know Facts For Your Next Test

1. The Ziehl-Neelsen technique is essential for diagnosing diseases like tuberculosis.
2. Acid-fast bacteria retain the primary stain (carbol fuchsin) even after being treated with acid-alcohol.
3. Heat acts as a mordant in the Ziehl-Neelsen technique to enhance dye penetration into the bacterial cell wall.
4. Non-acid-fast bacteria will lose the primary stain during decolorization and take up the counterstain (methylene blue).
5. The method differentiates between acid-fast bacilli (red/pink) and non-acid-fast organisms (blue).

Related terms

Acid-Fast Bacteria: Bacteria that retain certain dyes when treated with acid-alcohol, notably Mycobacterium species.

Carbol Fuchsin: A red dye used as the primary stain in Ziehl-Neelsen staining to penetrate bacterial cells.

Methylene Blue:

A blue dye used as a counterstain in various microbiological staining techniques, including Ziehl-Neelsen.