A problem with ________ of cell number is that dead cells also scatter light.
A) direct microscopic counts
B) viable counts
C) spread plate counts
D) pour plate counts
E) optical density measurements

Question

Quizplus · Accepted Answer

Optical density measurements use light scattering to determine cell density. However, this method cannot distinguish between live and dead cells, so dead cells will also contribute to the measured optical density. Therefore, optical density measurements have a problem with the accurate counting of cell number. The other methods listed, such as direct microscopic counts, viable counts, spread plate counts, and pour plate counts, are all capable of distinguishing live from dead cells and are not affected by this problem.

A Problem with ________ of Cell Number Is That Dead