Infection & ResponseKey Facts
Required Practical: Investigating Antibiotic Action
Part of Antibiotics and Drug Resistance — GCSE Biology
This key facts covers Required Practical: Investigating Antibiotic Action within Antibiotics and Drug Resistance for GCSE Biology. Antibiotic function, bacterial resistance evolution, responsible use, global health impact It is section 4 of 19 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 4 of 19
Practice
20 questions
Recall
24 flashcards
Required Practical: Investigating Antibiotic Action
Disc Diffusion Method
Aim: To investigate the effectiveness of different antibiotics against bacterial growth
Method:
- Prepare sterile agar plates
- Spread bacterial culture evenly across the plate
- Place antibiotic discs on the surface
- Incubate at 25°C for 24-48 hours
- Measure zones of inhibition around each disc
Results Interpretation:
- Large zone: Antibiotic is very effective
- Small zone: Antibiotic has limited effectiveness
- No zone: Bacteria are resistant to the antibiotic
Aseptic Techniques:
- Work near a Bunsen burner flame for sterile updraft
- Flame bottle necks before and after use
- Use sterile equipment (autoclave sterilization)
- Handle petri dish lids carefully - don't lift fully
- Seal plates with tape after inoculation