Definitions for "MULTIPLICITY OF INFECTION"
The ratio of number of infectious units of oncolytic virus to number of cells.
(abbreviated MOI) is the average number of viruses per cell. The MOI is determined by simply dividing the number of viruses added (ml added x PFU/ml) by the number of cells added (ml added x cells/ml). The average number of viruses per cell in the population could be 0.1, 1, 2, 10, etc, depending upon how you set up the experiment. Although the MOI tells you the average number of virues per bacterium, the actual number of virues that infect any given cell is a statistical function. For example, if the MOI is 1, some cells will get infected with one virus but some cells may be infected with 0 virus and other cells infected with two viruses.
The ratio of pathogen to host cells during an infection. For example, the ratio of phage P22 to Salmonella cells, or the ratio of Salmonella to cultured macrophages.