A sample of milk is tested for its bacterial content in a plate count assay. A one- milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained
A) 54 cells.
B) 540 cells.
C) 5400 cells.
D) 54,000 cells.
E) 540,000 cells.

Question

Quizplus · Accepted Answer

The third dilution in a 1:10 series is a 1:1000 dilution. If 54 colonies are counted from this dilution, the original sample contained 54,000 cells (54 colonies x 1000).

A Sample of Milk Is Tested for Its Bacterial Content