Describe how the scientists could use aseptic techniques to transfer 0.3 cm³ of C - AQA - A-Level Biology - Question 8 - 2022 - Paper 1
Question 8
Describe how the scientists could use aseptic techniques to transfer 0.3 cm³ of C. difficile in liquid culture from a bottle onto an agar plate.
[3 marks]
Worked Solution & Example Answer:Describe how the scientists could use aseptic techniques to transfer 0.3 cm³ of C - AQA - A-Level Biology - Question 8 - 2022 - Paper 1
Step 1
Use of Sterile Equipment
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Answer
The scientists should use sterilized pipettes or inoculating loops to prevent contamination. These tools must be autoclaved or disinfected before coming into contact with the liquid culture.
Step 2
Flame to Maintain Aseptic Conditions
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Answer
Before transferring the sample, the scientists should flame the mouth of the culture bottle to kill any unwanted microorganisms. This practice minimizes the risk of contamination from the air.
Step 3
Transfer Technique
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Answer
Carefully draw 0.3 cm³ of the C. difficile culture into the sterile pipette or onto the inoculating loop. Immediately transfer this volume onto the agar plate in a zigzag pattern to spread the culture evenly across the surface.
