Question

Which statement among A-D is false regarding the standard plate count method?

Answer 1

Answer:

The correct answer is option E. "None of A-D is false; all are true statements".

Explanation:

The standard plate count involve different considerations including the ones listed:

A. It utilizes a standard dilution procedure called serial dilution. Most of the time culture plates have thousands of cells growing in it, it is necessary to use a standard dilution in order to make the counting feasible.

B. It measures both live and dead cells in the liquid sample. The standard plate count procedure uses a dye such as crystal violet to differentiate among live and dead cells. Both should be counted and the percentage of viability should be reported as well.

C. A countable plate in the procedure is one having 30 to 300 CFUs on it. Between 30 to 300 CFU is considered a countable plate since less than 30 will be make errors in dilution to be considerable and more than 300 is difficult to count and tend to form cell aggregates.

D. It is a viable count method to quantitate cell density of a liquid sample. This is true as long as the cells in the liquid sample are able to growth in a standard plate as well, since the cells must adhere to the counting device in order to perform the procedure.