Question 3

Serial dilutions can be used to estimate the size of a bacterial population in a culture.

A scientist used $cm325\text{ cm}^3$ of a bacterial culture that contained $2.0 \times 10^6$ bacterial cells.

$4%4\%$ of the $cm325\text{ cm}^3$ culture was transferred to a new test tube and made up to $cm320\text{ cm}^3$ with water.
An additional five-fold dilution was carried out, which produced a final $cm320\text{ cm}^3$ solution.
$cm30.2\text{ cm}^3$ of the final $cm320\text{ cm}^3$ solution was transferred to an agar plate.

Each colony that developed on the agar plate was assumed to represent a single bacterial cell in the bacterial culture.

Estimate the number of colonies that you would expect to develop on the agar plate.

Serial dilutions can be used to estimate the size of a bacterial population in a culture.

A scientist used $cm325\text{ cm}^3$ of a bacterial culture that contained $2.0 \times 10^6$ bacterial cells.

$4%4\%$ of the $cm325\text{ cm}^3$ culture was transferred to a new test tube and made up to $cm320\text{ cm}^3$ with water.
An additional five-fold dilution was carried out, which produced a final $cm320\text{ cm}^3$ solution.
$cm30.2\text{ cm}^3$ of the final $cm320\text{ cm}^3$ solution was transferred to an agar plate.

Each colony that developed on the agar plate was assumed to represent a single bacterial cell in the bacterial culture.

Estimate the number of colonies that you would expect to develop on the agar plate.

Practical skills