Abstract
Cells infected with flavivirus release various forms of infectious and non-infectious particles as products and by-products. Comprehensive profiling of the released particles by density gradient centrifugation is informative for understanding viral particle assembly. However, it is difficult to detect low-abundance minor particles in such analyses. We developed a method for viral particle analysis that integrates a high-sensitivity split luciferase system and density gradient centrifugation. This protocol enables high-resolution profiling of particles produced by cells expressing Japanese encephalitis virus factors.