Question 4

Serial dilutions are commonly used in environmental monitoring to estimate the concentration of microorganisms in a water body.

An environmental scientist collected a $cm340\text{ cm}^3$ pond water sample containing $1.5 \times 10^7$ microalgae cells.

$5%5\%$ of the $cm340\text{ cm}^3$ sample was transferred to a test tube and made up to $cm325\text{ cm}^3$ with distilled water.
An additional eight-fold dilution was carried out, which produced a final $cm340\text{ cm}^3$ solution.
$cm30.16\text{ cm}^3$ of this final $cm340\text{ cm}^3$ solution was transferred to a hemocytometer slide.

Each microalgae cell counted on the slide corresponds to a single viable cell in the portion of the sample.

Serial dilutions are commonly used in environmental monitoring to estimate the concentration of microorganisms in a water body.

An environmental scientist collected a $cm340\text{ cm}^3$ pond water sample containing $1.5 \times 10^7$ microalgae cells.

$5%5\%$ of the $cm340\text{ cm}^3$ sample was transferred to a test tube and made up to $cm325\text{ cm}^3$ with distilled water.
An additional eight-fold dilution was carried out, which produced a final $cm340\text{ cm}^3$ solution.
$cm30.16\text{ cm}^3$ of this final $cm340\text{ cm}^3$ solution was transferred to a hemocytometer slide.

Each microalgae cell counted on the slide corresponds to a single viable cell in the portion of the sample.

Practical skills assessed in the practical endorsement