Plaque assay of bluegill virus using a methylcellulose overlay

The EFDL strain of Bluegill virus (BGV) has been titrated in BF-2 cells by the plaque method using 1% methylcellulose overlay. Visible plaques, formed 7 days postinfection, ranged in diameter from 0.5 to 1 mm. Dose-response experiments indicated that a single particle initiated the formation of a plaque. The titration of BGV by this new plaque method provided an accurate technique for the determination of virus concentration.