Virus Infectivity Titer
Viral infectivity is defined as the number of virus particles capable to invade a host cell.
This is determined by using susceptible cells to the specific virus by measuring the viral infectivity.
The viral titer can be measured by such means as the TCID50 method or the plaque method, and the like, but these methods rely on the morphological change of the cell when it has been infected by the virus.
