Question

Which of the following is an advantage of the direct microscopic count?

A) can easily distinguish live from dead cells
B) requires a large number of cells
C) sample volume is unknown
D) requires no incubation time
E) can readily count organisms that are motile

Answer 1

The direct microscopic count's advantage is that it requires no incubation time.

Step-by-step explanation:

The advantage of the direct microscopic count is that it requires no incubation time. The direct cell count method provides an immediate estimate of total cells in a sample using a specialized slide like the Petroff-Hausser chamber and a microscope. Although it can't easily distinguish live from dead cells without additional staining techniques, such as fluorescence staining with viability stains, it is a fast and direct method of estimation. This method may not be suitable for counting motile or very dilute cultures as it does not differentiate between live and dead cells without special stains and may not have enough cells to count, respectively.