Protocols

Steaking/Plating Microbial Cultures on Agar

Goal: To isolate and grow isolated cultures of E. coli on Agar plates

Materials:
Bunsen burner
Disposable loops used to streak plates Lysogeny broth(LB) agar plates (with antibiotics if required)
Culture of E. coli (in plate or in shake flask/test tube)

Procedure:
1. Ignite the Bunsen burner to maintain a sterile environment
2. If culture is in a petri dish: Use the tip of a disposable loop and pick up an isolated culture
3. If culture is in a shake flask/test tube: Dip the circular end of the loop into the liquid medium culture
4. Close the petri dish or shake flask/test tube
5. Transfer the collected sample to the LB agar plates by gently touching the tip/loop end with bacteria on the agar and brush over the plate. Make sure to streak at an angle
6. Two streaking methods are possible: Brushing the loop all over the plate once without crossing previous streaks, or brushing the loop over three different thirds of the plate
7. Allow streaks to dry before labelling each plate and incubating them at the appropriate temperature

Inoculating Cultures in Liquid Media

Goal: To isolate and grow individual colonies of E. coli in a nutrient-rich media

Materials:
Test tubes/Shake flask
Media (Lysogeny Broth)
Petri dishes containing E. coli culture
Pipettes
Antibiotics (if required)
Bunsen burner

Procedure:
1. Ignite the Bunsen burner to maintain a sterile environment
2. Obtain a shake flask/test tube and transfer the desired amount of media into the flask/tube. If required, add the appropriate amount of antibiotics
3. Open the petri dishes containing the E. coli cultures. Use a pipette tip and carefully pick a single colony from the plate
4. Transfer the colony on the pipette tip to the media in the flask/tube
5. Label the flask/tube and incubate in a shaker at an appropriate temperature