RP 6 - Aseptic Techniques

• The Aseptic technique is used when working with microorganisms. It keeps the culture medium sterile and prevents contamination with any unwanted bacterial species.
• Aseptic Techniques:

  • Wash hands to kill micro-organisms or wear gloves to prevent contamination.
  • Work close to a hot burning Bunsen burner to create an upward current of air.
  • Disinfect the bench to kill micro-organisms and to prevent contamination.
  • Pass equipment through a flame to kill micro-organisms and prevent contamination.
  • Lift agar plate lids slightly to prevent entry of unwanted micro-organisms.
• Growing bacteria on agar.

  1. Use aseptic technique to prevent the contamination of equipment.
  2. Inoculate (spread) one species of bacteria onto an agar plate then add 4 discs that contain different antimicrobials.
  3. Incubate the plates at the same temperature for the same length of time: bacteria will asexually reproduce during this period.
  4. Measure the diameter of the inhibition zone and calculate its area.
  5. The more effective the antimicrobial, the larger the inhibition zone, so the more bacteria that were killed.
• Growing bacteria on agar.

  Water was used as a control with the antimicrobials.
• In order to create the zone of inhibition the antimicrobials must diffuse through agar.