Klapperich Lab:Streaking bacteria on Agar plate
This protocol describes the procedure for streaking bacteria on an Agar plate.
- Agar plate(s)
- Bacteria sample from old plate
- Inoculation loop
- Bunsen Burner
- 70% Ethanol
- Wipe down the bench with 70% EtOH and start a Bunsen burner flame.
- Label new agar plate(s), on the bottom, with your initials, the date and strain of bacteria, and prepare plastic beaker for containing the disposable at the side.
- Flame until red to disinfect the inoculation loop, from top toward the loop, and allow it to cool down by inserting to loop into the agar at a corner of the new agar plate.
- (work by the flame) Open the old streaking plate, wipe down water vapor on the cover with Kimwipes, and take one (1) pure culture with the loop.
- Slide the loop over the new agar plate. First start circulating ~10 times at a corner of the streaking area, followed by moving the loop in zigzag patterns to spread the colony on all 4 quadrants over the plate. Between each spread, flame the loop to disinfect and allow it to cool down. Cross over the previous quadrant 2~3 times and avoid cross over the previous quadrant more than once or into any other quadrants for the last streak.
- Cover the new dish and seal the edge of the old plate with parafilm.
- Incubate the new plate @37C in a upside-down position (to allow water to drip onto the cover) overnight (~24hrs)
- Bleach and wipe down the bench with 70% EtOH again at the end.
- Take the plate(s) out from the incubator on the next day and store it inside the fridge with parafilm sealing the edge. (good for a month)
- Bleach the old dish (entirely cover the plate) and seal with parafilm. Dispose it in the biohazard trash.
- The new streaking plate is good for a month. Bacteria needs to be re-streaked every month.
- Streaking plate should be always stored in upside-down position.