Calculating the effect of antibiotics and antiseptics
The effectiveness of the chosen antibiotic or antiseptic can be measured numerically by using the formula \(\pi\)r2. Using the diagram below
- For \(\pi\) use 3.14. This value may vary slightly in a specific question.
- Measure the diameter of the zone of inhibition and divide it by 2 eg 10 Ă· 2 = 5 mm
- Use the equation: \(\pi\)r2
For example: 3.14 Ă— 52 = 3.14 Ă— 25 = 78.5 sq mm