When Doing a Plaque Assay with Human or Animal Cells

Multiple Choice

When doing a plaque assay with human or animal cells, a layer of nutrient media mixed with agar is put on top of the cells after they have been infected with the diluted virus.What is the major purpose of this agar layer?

A) It helps to feed the cells as they grow.
B) It promotes the replication of the virus.
C) It makes the infected cells easier to visualize.
D) It limits the movement of virus particles.
E) All of the above are correct.