Mar 27, 2024

Public workspaceStreaking bacteria on a Petri Plate from -70C frozen culture

DOI
https://dx.doi.org/10.17504/protocols.io.q26g7898qlwz/v1
  • Emma Tollafield1,
  • Dibyendu Dutta1,
  • Wolfram Moebius1
  • 1University of Exeter
Emma Tollafield
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DOI: https://dx.doi.org/10.17504/protocols.io.q26g7898qlwz/v1
Protocol Citation: Emma Tollafield, Dibyendu Dutta, Wolfram Moebius 2024. Streaking bacteria on a Petri Plate from -70C frozen culture. protocols.io https://dx.doi.org/10.17504/protocols.io.q26g7898qlwz/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
Standard Microbiological Protocol, used regularly.
Created: May 25, 2021
Last Modified: March 27, 2024
Protocol Integer ID: 50207
Keywords: streaking bacteria, isolated single colonies of any bacterial strain, petri plate, bacterial strain, bacteria, streak plating, frozen culture, isolated single colony
Abstract
This protocol describes how to obtain isolated single colonies of any bacterial strain by streak plating, from a -70C frozen stock culture.
Materials
  • Inoculation loops
  • Frozen E.coli BW25113 stock
  • Pipette and tips
Creating a streak plate
Label bottom of LB agar plate with name, date, E. coli strain, and any additional contents such as antibiotics.

Note
Streak plates from stocks should be replaced weekly and are kept in the blue tray in the small fridge nearest our bench.

Working aseptically, use inoculation loop to take E. coli from the frozen stock by swirling loop on surface of stock until slushy.
Note
Note: Alternatively, a pipette tip can be used to take from E. coli stock and to produce streaks. This will further help to avoid contamination.


Streak loop across one side of the agar plate. Discard loop (if using disposable plastic loop).
Rotate the plate 90°, and starting at the end of the last set of streaks, use a fresh disposable loop (or sterilize the reusable loop) to create streaks on this side of the plate. Working clockwise, repeat with next two sides of the plate, using a fresh loop each time.
Incubate plate DurationOvernight atTemperature37 °C , upside down to prevent condensation.