1
Q
Serial dilution
A
Step-by-step dilution to reduce bacteria concentration.
example:
10⁻¹
10⁻²
10⁻³
10⁻⁴
2
Q
Why we do it
(serial dilution)
A
To count bacteria accurately.
3
Q
Countable plate
A
30 – 300 colonies
Reason:
Statistically reliable.
4
Q
Viable count
A
Counts living cells only.
5
Q
CFU calculation
formula:
A
CFU/mL =
colonies ÷ dilution plated
Example:
50 colonies from 10⁻⁶
CFU =50 × 10⁶
