Improved methods using HVJ(Sendai virus) for introducing substances into cells.

When HVJ virions were sonicated in the presence of a given protein, about 0.2%–0.3% of total protein added was recovered in the virions. The protein molecules could be introduced effectively into cells. In this study, fragment A of diphtheria toxin was used as the test protein. More than 96% of L cells were killed after short exposure to the virus suspension containing fragment A diluted so as to contain only about 0.004 μg of fragment A per ml.