3.6.2: Urease Test Activity

In this activity you will test two bacterial samples. Label each urea agar tube with the sample it is to be inoculated with.

1. Turn on the Bunsen burner and sterilize the inoculating needle by passing it through the flame of the burner.
2. Gently raise the lid to the agar plate containing the bacterial culture to be sampled and touch the inoculating needle to a bacterial colony to obtain a bacterial sample.
3. Pick up the urea agar tube to which the sample is to be transferred. Remove the cap and pass the mouth of the tube through the flame of the Bunsen burner.
4. Insert the inoculating needle by stabbing straight all the way down into agar. Pull the needle back out slowly without disturbing the stab
5. Pass the mouth of the urea agar tube through the flame and recap it, and return it to the test tube rack.
6. Sterilize the inoculating needle by flaming the loop in the flame of the Bunsen burner. Repeat steps 1 - 8 for the second bacterial species and urea agar tube to be inoculated.
7. Incubate the inoculated urea agar tubes at 37°C for 24 hours.
8. Observe the urea agar tube for color changes. Record your results in the table below.

In the table below write the name of the species tested and the results for each of the tests performed.

Experimental Results

Bacterial Species	Color of urea agar after incubation	Urease Test Results

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