(redirected from moiety of infection) Also found in: Acronyms.
multiplicity of infection
The ratio of viral or phage particles to cells in a system to infection targets (e.g., cells in a defined volume).
multiplicity of infection (MOI)
(virology) the ratio of infectious virus particles to susceptible CELLS. A high MOI indicates that a lot of virus particles (VIRIONS) are present in the system, relative to susceptible cells.