1. Streaking is frequently used to purify a stock or to propagate stock. Agar culture plate should be dry before streaking. Invert the plate, and leave it in 37 °C incubator for awhile until there is no visible water on the surface of the agar.

2. Light a small flame and keep opened plates, or media near the flame.

3. Dip the inoculation loop into 70% ethanol in a bottle. Flame the loop and wait until the loop is cool.

4. Gently touch the loop on a single colony or a stock solution. Streak on the agar plate.

5. Sterilize the loop again, start from where you left off and streak in a different direction.

6. Repeat step 5.

7. Put the plate in a 37 °C incubator overnight. Single colonies should form around the streaking path.