Question

Which of the following techniques involves the use of three sets of five culture tubes each to estimate the number of bacterial in a sample

A) membrane filtration
B) metabolic activity
C) most probable number
D) microscopic counts
E) coulter counter

Answer 1

The Most Probable Number (MPN) (Option c) method uses sets of culture tubes to statistically estimate bacterial counts in a sample, and is particularly useful for dilute samples.

Step-by-step explanation:

The technique that involves the use of three sets of five culture tubes each to estimate the number of bacteria in a sample is known as the Most Probable Number (MPN) method. This is a statistical procedure used for estimating the number of viable microorganisms in a sample, particularly when the samples are too dilute for other methods like plate counts. A typical application of this technique includes the estimation of the number of coliforms in a sample of water or in food products. Culture tubes are inoculated with different volumes of the sample, and bacterial growth is then assessed through a change in color due to metabolic activity, such as lactose fermentation.