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Oxidase Test

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  Cytochrome oxidase – this test determines the presence of cytochrome oxidase enzymes. 

     Oxidase reagent

Tetramethyl-P-Phenylenediamine Dihydrochloride         1.0g
d-H2O                                                                               100 mL



The use of an iron-containing metal inoculation loop can lead to a false- positive reaction. Use only plastic or platinum loops for this test.
Image result for Oxidase Test1.      Add an inoculum of pure 18 -24 hour old bacterial culture to the test strip impregnated with reagent.

 RESULTS:
           
Positive: purple color within 5-10 seconds (reactions that occur after 10 seconds are negative).(Pseudomonas, Neisseria, Alcaligens, Aeromonas, Campylobacter, Vibrio, Brucella, Pasteurella, Moraxella, Helicobacter pylori, Legionella pneumophila, etc.)
    
Negative: no purple color.(  Family Enterobacteriaceae )

Quality Control
  Positive: Pseudomonas aerugenosa 
 Negative: Escherichia coli
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