3.4.6: Citrate Test Activity

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

1. Sterilize the inoculating needle by placing it in the Bunsen burner, then allow it to cool for 15 – 30 seconds.
2. Obtain a sample of bacteria #1 by touching a colony of the bacteria on the agar plate using a aseptic technique.
3. Pick up the Simmons Citrate Agar Slant labeled tube #1, remove the cap and pass the mouth of the tube through the flame of the Bunsen burner.
4. Insert the needle with the bacterial sample into the tube, stabbing into the bottom of the media and then gently streak up the surface of the media.
5. Pass the mouth of the tube through the flame, recap the tube and return it to the test tube rack.
6. Sterilize the inoculating loop.

Repeat steps 2 – 7 for bacterial sample #2.

7. Place the rack with both Simmons Citrate Agar Slant tubes in an incubator at 37°C for 24 hours.
8. After 24 hours observe your samples to determine your results and record your data 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 after Incubation	Citrate Test Results

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