Bacterial Culture Handling and Experimentation

Dr. Becks guides students through a microbiology practical involving safe handling of E. coli. The tutorial covers preparing agar plates, inoculating them with bacteria, and testing the effectiveness of antibiotics and antiseptics. Students learn to maintain sterile conditions, label plates, and analyze results to understand bacterial growth and inhibition. The practical is part of the new science GCSE curriculum, and additional training is available through the Aden Teaching School Alliance.

What is the primary reason for handling the E. coli strain as if it were dangerous?

• It is resistant to antibiotics.

• To maintain a sterile environment.

• It is a highly infectious strain.

• To prevent it from mutating.

Why is it important to label the bottom of the agar plate?

• To identify the type of bacteria and date.

• To make it easier to store.

• To prevent contamination.

• To ensure the lid stays on.

What is the purpose of using a blue flame on the Bunsen burner during the inoculation process?

• To heat the agar plate.

• To create a sterile environment.

• To dry the bacterial culture.

• To sterilize the pipette.

What is the main risk when handling the bacterial culture?

• Spilling the culture.

• Inhaling the bacteria.

• Burning the agar plate.

• Contaminating the culture.

Why is it important to spread the bacterial culture evenly over the agar plate?

• To ensure even bacterial growth.

• To prevent the agar from drying out.

• To make the plate look neat.

• To avoid contamination.

What is the purpose of using different discs soaked in substances like tea tree oil and antibiotics?

• To change the color of the agar plate.

• To observe the effects on bacterial growth.

• To test the growth rate of bacteria.

• To sterilize the agar plate.

How can you determine which substance is most effective at inhibiting bacterial growth?

• By counting the number of bacterial colonies.

• By observing the color change in the agar.

• By measuring the diameter of the clear area around the disc.

• By checking the smell of the plate.

What is a potential issue with sealing the agar plate completely with tape?

• It makes the plate too heavy.

• It creates anaerobic conditions.

• It allows oxygen to enter.

• It prevents bacteria from growing.

Why is it important to consider the viscosity of the liquids used on the discs?

• To prevent them from evaporating.

• To ensure they are absorbed by the agar.

• To make them easier to handle.

• To ensure they spread evenly.

What is a key consideration when applying the results of this experiment to real-world scenarios?

• The color of the substances.

• The ease of obtaining the substances.

• The potential side effects of the substances.

• The cost of the substances used.