• The motility of many bacteria is due to the presence of thread like appendages called flagella.
  • Flagella are a thin proteinaceous structure which is originate from cytoplasm and comes out from the cell wall.
  • Types of flagellar patterns:
  • Monotrichous: single flagellum at one end.
  • Lophotrichous: many flagella at one end.
  • Amphitrichous: flagella on both ends.
  • Peritrichous:  flagella all over the surface.


  • For staining of flagella, Ziehl’s carbol fuchsin is commonly used.
  • Carbol fuchisn is a mixture of basic fuchisn and phenol which has great affinity towards the mycolic acids found in cell membrane of bacteria.
  • In addition, the stain contains tannic acid and potassium alum used to coat and thicken the flagellum to make it visible.


  • 18 hours old culture of proteus vulgaris
  • Flagella mordant
  • Ziehl’s carbol fuchsin
  • Glass slide
  • Dichromate solution
  • 95% alcohol
  • Distilled water
  • Wash bottle
  • Inoculating loop


  • Take the slide and dip in dichromate solution then wash with water and rinse with 95% alcohol, pass the slide through flame and allow it to cool.
  • Prepare the bacterium suspension in distilled water and incubate for 10-15 minutes at room temperature.
  • Place a loop full of the sample on one of the edges of the slide.
  • Tilt the slide to make the drop spread on the slide and a thin film in prepared.
  • Leave the slide to air dry the smear.
  • Cover the smear with flagella mordant and leave for 10 minutes.
  • Wash the slide with distilled water.
  • Flood the carbol fuchsin on the slide and leave for 5 minutes.
  • Wash the slide with distilled water.


  • Under the microscope the bacterial cell appear pink with deep stained rod, flagella with pink colour on the outer coat.


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