Dengue virus particles are concentrated from tissue culture supernatant by precipitation and ultracentrifugation. Antigen is purified by sucrose density gradient centrifugation. Virus particles are separated from the sucrose containing buffer by ultracentrifugation before resuspension in Medium 199.

The antigen preparation is inactivated by room temperature incubation with formaldehyde. The formaldehyde is neutralised by the addition of sodium bisulphite.

This product has been rendered inactive by standard procedures. However this material should still be handled as infectious and should be disposed of appropriately.