Question

4. What reaction would you expect when performing a positive control in the oxidase assay? What would it mean if a known oxidase-positive bacterium did not cause the expected reaction?

Answer 1

We perform oxidase assay to check the activity of oxidase enzyme. In any experiment, we use positive and negative control.

Positive control is the test tube which contains all the solutions along with the enzyme to be checked. In this test you will get a positive reaction, that is, the enzyme will react with its substrate. If in case we do not get the reaction, it means that any of the solutions or the substrate or any instrument is not working well.

Negative control is the test tube which contains all the solutions along with the enzyme to be checked but not the substrate. In this test tube you will not get a positive reaction, that is, without the substrate the enzyme will not react. We use this to ensure that the enzyme does not give any false result by binding to any of the solutions, that is, to ensure that the enzyme will bind to the specific substrate.

In case we do not get any reaction in oxidase positive bacteria it means that any of the substrate or any other solution which we have used in the experiment or any of the instruments or the enzyme itself is not working properly.

If you find the answer useful than please hit the like button.