Microbiology

• what is the aim?

  to investigate the effect of antiseptics or antibiotics on bacterial growth using agar plates and measuring zones of inhibition?
• what are the variables?

  INDEPENDENT - type of antiseptic or antibiotic applied

  DEPENDENT - diameter of zone of inhibition

  CONTROL - temperature of incubation, concentration of antiseptics and antibiotics, duration of incubation
• what is the purpose of dividing the agar plate into three sections?

  to compare the effect of different antiseptics
• why is it important to wash hands with antibacterial soap before handling the filter paper discs?

  to remove any potential contaminants from the hands
• at what temperature and how long for should you incubate the agar plate?

  25* for 48 hours
• what is the purpose of incubating the agar plate at a warm temperature for two days?

  to allow bacteria to grow and form colonies
• what is the purpose of spraying the work surface with disinfectant?

  to clean and remove potential contaminants
• Who is conducting the microbiology practical?

  Dr. Becks
• What type of bacterial culture is being used in the practical?

  A safe strain of E. coli
• Why must you handle the bacterial culture as if it were dangerous?

  To maintain safety and sterility
• What is the first step before handling the microbe?

  Set up equipment and wash hands
• Where should the agar plates be opened during the procedure?

  Near the Bunsen burner
• How should the agar plate be labeled?

  Label the bottom, not the lid
• Why is it important to write the date on the agar plate?

  To track how old the culture is
• What is the purpose of marking the agar plate into three sections?

  To apply different treatments for comparison
• What is the role of the Bunsen burner in the procedure?

  To create a sterile environment
• What should you do if you touch a non-sterile surface?

  Wash your hands immediately
• How do you create a sterile environment before inoculating the plate?

  Turn the Bunsen burner to blue flame
• What is the significance of using a sterile pipette?

  To prevent contamination of the culture
• How should the lid of the bottle be handled during the procedure?

  Flame the lid gently
• What should you do after inoculating the agar plate?

  Seal the lid with tape
• Why is it important to store agar plates upside down?

  To prevent condensation on the agar
• What does a cloudy agar plate indicate?

  Bacteria are growing on the plate
• What do clear areas around the disks represent?

  Areas where bacteria cannot grow
• How can you measure the effectiveness of the treatments?

  Measure the diameter of clear areas
• What factors should be considered to ensure a fair test?

  Viscosity of liquids and diffusion rates
• Why is it important to consider real-world applications of the results?

  To determine effective treatments for infections
• What is the purpose of using different disks in the experiment?

  To compare the effectiveness of treatments
• What should you do after completing the practical?

  Disinfect your work area
• Why is maintaining a sterile environment crucial during the experiment?

  To prevent contamination of bacterial cultures
• What is the correct method for inoculating the agar plate with bacteria?

  Squirt culture with minimal lid opening
• What is the purpose of using antibiotics and antiseptics in the experiment?

  To test their effectiveness against bacteria
• What is the incubation temperature for the agar plates?

  30 degrees centigrade
• What does the presence of clear areas around the disks indicate?

  Inhibition of bacterial growth
• How can the results of the experiment be applied to real-world situations?

  To improve treatments for bacterial infections
• What is the role of the teacher during the practical?

  To oversee and store the agar plates
• Why is labeling important in a laboratory setting?

  To track samples and avoid confusion
• how is an agar plate made?

  hot agar jelly is poured in a petri dish and inoculating loops or a sterile dropping pipette are used to transfer microorganisms
• what temperature are cultures of microorganisms kept at and why?

  25* because harmful pathogens can grow
• how can you investigate the effect of antibiotics on bacterial growth?

  1. place paper discs in different types of antibiotics on an agar plate that has an even covering of bacteria. leave some space in between the discs
  2. antibiotic will diffuse into the agar. antibiotic resistant bacteria will continue to grow around the discs. a clear area will be left where the non-resistant bacteria died - this is called the inhibition zone
  3. CONTROL - soak paper disc in sterile water
  4. leave the plate at 25* for 48 hours
  5. the more effective the antibiotic the larger the inhibition zone