Oxidase test

• Identifies cytochrome C oxidase by testing for the ability to oxidize tetramethyl-p-phenylenediamine to indophenols, which are purple
• The test is positive when it turns purple within 10 seconds
  • Must be done from plain 5% SBA
• All oxidase-positive bacteria are aerobic
  • P: Pseudomonas spp.
  • V: Vibrio cholerae
  • N: Neisseria spp.
  • C: Campylobacter spp.
  • H: Helicobacter spp. / Haemophilus spp.
  • Aeromonas spp.

Further Reading

• Microbe Online. Oxidase Test: Principle, Procedure and Oxidase-Positive Organisms.