In a plaque assay a microbiologist counts 20 plaques on a pl

In a plaque assay, a microbiologist counts 20 plaques on a plate. How many plaque-forming units can be assumed to have been present in the original bacterium-virus mixture on the plate, if there was no dilution of the mixture prior to plating?

2

10

20

40

Solution

2^number of generations * initial number of bacteria = total no. of bacteria present after n generations.

assuming no. of generations is 1(not specified in the question),

2¹ * y =20

2y=20

y=20/2=10

so, the initial count must be 10.