Plaque assays are often used to estimate the number of virions in a sample of a particular volume (the titer). The count is given as plaque-forming units. Which of the following is NOT generally a concern that must be considered in evaluating the results of plaque assays?

The largest problem is that single viruses may create multiple plaques, resulting on overestimates of the number of viruses present.

Explanation:

Plague assay allows to measure the concentration of viruses in a sample, it is a widely used approach for determining the quantity of infectious virus. Therefore the amount of plaques created by a single virus is not a concern when evaluating the results of plaque assays.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

correct answer is a. and d.