Plaque assay of nuclear polyhedrosis viruses in cell culture.
The nuclear polyhedrosis virus of Autographa californica has been titrated in Spodoptera frugiperda cells by the plaque method, using a solid overlay which does not require either the use of modified culture medium or expensive purified agarose or the addition of culture medium as a liquid layer above the solid agarose. This assay is more sensitive than that using a viscous methyl cellulose overlay but less sensitive than the end-point dilution technique. Neither Trichoplusia ni nor Bombyx mori cells were satisfactory as indicators for the assay as described, since they failed to form a stable monolayer. Manduca sexta cells could be utilized for assay of A. californica nuclear polyhedrosis virus, but the sensitivity was lower than with S. frugiperda cells.
Brown
M
M
Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
Faulkner
P
P