Hemagglutinating virus of Japan (HVJ) Envelope (HVJ-E) is a nonproliferative and noninfectiousvesicle about 300 nm in diameter on average purified after complete  inactivation of Sendai virus genomic RNA. Since the F protein distributed on the HVJ-Envelope has high membrane-fusing potential comparable to that of live virus,  it is possible to use HVJ-E itself as a cell-fusing agent or to introduce genes, proteins, anti-cancer agents, etc. in HVJ-E-incorporated form into cells for analysis  of their functions.

HVJ (Hemagglutinating virus of Japan) is also called Sendai virus (SeV) or Mouse Parainfluenza virus type 1