Antimicrobial Properties of Plant

• Role of aseptic techniques


  Aseptic technique is used to avoid contamination of the sample from outside substances such as microorganisms.

  • This is important to get reliable and repeatable data.
• Aseptic Techniques


  • Wipe surfaces w/ antibacterial cleaner before and after the experiment.
  • Use Bunsen burner to create convection currents that keep microbes away.
  • Flame the wire hoop before transferring bacteria.
  • Flame bottle necks to prevent contamination.
  • Minimize the time vessels containing bacteria are open.
  • Close windows and doors to limit air currents.
• Method for garlic


  1. Perform aseptic techniques.
  2. Crush 3g of garlic and mint (separately) with methylated spirit, shaking occasionally.
  3. Transfer plant extract to paper disc using a sterile pipette.
  4. Let paper discs dry for 10 minutes.
  5. Place paper discs on a petri dish using sterile forceps.
  6. Tape lid lightly, invert, and incubate at 25°C for 24 hours.
  7. Sterilize equipment and disinfect surfaces.
  8. Measure the inhibition zone diameter without removing the lid.

  Calculate the inhibition zone area using $π( 2 d ​ ) 2$
• Why is the bacteria sample incubated at 25°C instead of 37°C?

  Incubating at 25°C prevents the growth of harmful pathogens that could proliferate at 37°C (human body temperature).