Abstract
Sendai virus (Parainfluenza virus type I) formed the plaques on monolayer culture of kidney cells of 2 or 3 day old chicks. A linear relationship between the concentration of virus and the number of plaque was observed.
Plaque forming unit of Sendai virus with chick kidney monolayers was about one-third to one-tenth of that of 50% egg infectious doses. Growth of Sendai virus in chick kidney cell monolayer reached a maximum titer at 15 hours and production of infectious particles by single cell was calculated at about 25 plaque forming units.
