Ziehl-Neelsen Staining

This technique allows differentiation of most bacteria into two groups corresponding to cell wall type. Gram positive cells contain thick peptidoglycan with numerous techoic-acid cross-linkages which bind to the highly basic Crystal violet dye.

 

  • sample
    preparation
  • staining
    protocol
  • microscopic
    evaluation

 

Sample Preparation

 

Vortex the specimen - concentrated sediment, unconcentrated sputum, other purulent material, or stool. Aspirate 0.1-0.2 ml with a Pasteur pipet and place 2-3 drops on the slide. Using the pipette or a sterile applicator, slowly spread the liquid uniformly to make a thin smear. For CSF do somehting else...

Fix the smear at 80C for 15 minutes, or for 2 hours at 65-75 C on an electric hot plate.