Table 1. Inactivation of dengue-2 virus by formaldehyde, INA and AMT.

	Control Untreated Virus	INA (50uM) + UV (5 min.)	AMT (10mg/ml) + UV (3 min.)	Formaldehyde (5 d)
Plaque Assay	1.25 x 107 pfu/ml	No plaques detected	No plaques detected	No plaques detected
Immunofluorescence of infected vero cells.	++++ at highest dilution tested	Negative	Negative	Negative

Control and treated virus preparations were tested by direct plaque assay and immunofluorescence (IFA) of vero cells infected by treated virus and incubated for 7 d. IFA slides were scored as ‘+’, ‘++’, ‘+++’ or ‘++++’ to indicate approximately < 10%, 10–30%, 30–60% and > 60% cells infected.