1. Ex. 15 Oxidase Test Objectives: ?? Cytochrome oxidases help with transfer of electrons from cytochromes to oxygen.

2. Electron Transport Phosphorylation Textbook Fig 5.16

3. Oxidase Test Determines presence of certain cytochrome oxidases Use whenever Gram-neg. bacteria have to be identified When test reagent gets oxidized it changes color. Oxidase test is positive if color change within 15 seconds!

4. Only use on young cultures Table 15-1: Oxidase Test Results and Interpretation ResultInterpretation Symbol Dark blue within 15 secondsCytochrome c oxidase is present+ No color change to blue or blue after 15 seconds Cytochrome c oxidase is absent­ Oxistrip

5. Materials needed per table:  Oxidase reagent (bottle with dropper)  Small pieces of paper towel  sterile Q-tips (2 per student) Pure slant culture needed per table: 1.E. coli 2.Pseudomonas aeruginosa Each student should individually do the oxidase test for both bacterial species.