Investigating antimicrobial

• What is the purpose of the practical investigation of antimicrobials?

  To test the action of antimicrobials
• What is used to grow microorganisms in the practical?

  Sterilised agar jelly in a Petri dish
• What is the role of the inoculating loop in the experiment?

  To move microorganisms to the agar jelly
• Why is a control disc used in the experiment?

  To compare the effect of the antibiotic
• What does a 'clear zone' indicate in the experiment?

  Area where bacteria can't grow
• What happens to the bacteria during the incubation period?

  They multiply and cover the jelly
• At what temperature are cultures kept in the school lab?

  25°C
• Why are higher temperatures used in industry for microbial growth?

  To allow microbes to grow faster
• What precautions should be taken to avoid contamination in the culture?

  • Regularly disinfect work surfaces
  • Sterilise equipment before and after use
  • Work near a Bunsen flame
  • Flame the neck of the glass container
• What should be done to inoculating loops before use?

  They should be sterilised by flame
• Why is it important to keep things sterile in the experiment?

  To prevent the growth of harmful microbes
• What is the significance of flaming the neck of the glass container?

  To prevent unwanted microbes from entering
• What is the main reason for using a control disc in the experiment?

  To ensure antibiotic effect is measured
• Why is it important to investigate the effectiveness of different antibiotics?

  • To determine which antibiotics are effective
  • To understand bacterial resistance
  • To improve treatment options for infections