Student Sheet

Sterile Technique

Purpose of Sterile Technique:

1. Flaming:  You must be very careful when transferring bacteria from a culture to a a slide or petri disk.  Microbiologists normally use a metal wire loop or needle for this. The wire can be sterilized by heating it over a bunsen burner until it is red hot. You start flaming the wire loop from the handle connection up to the tip. This will prevent the liquid at the tip from spraying into the air. Once the needle cools it can then be used to transfer bacteria.

2. Preventing Contamination of a Culture tube: Pickup the culture tube with your non-dominant hand. Hold the wire loop in your dominant hand. Remove the cap of the culture tube with the small finger of the wire loop hand and hold the cap. Flam the lip of the culture tube for a few seconds. Remove a sample. Flam the lip of the culture tube and replace the cap.

3. Step by step procedure

  1. Pick up culture tube from rack with non-dominant hand and and wire loop with dominant hand.
  2. Flam wire loop.
  3. Remove cap from culture tube - hold cap.
  4. Flam culture tube lip.
  5. Insert loop end of wire loop into culture tube and remove a small sample.
  6. Flam lip of culture tube and replace cap.
  7. Put culture tube back into the rack from where it came.
  8. Streak sample over slide or ?
  9. Flam wire loop.

To clean up you wipe down the work area with a 10% bleach solution. Before leaving, wash your hands with soap.

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