Purified DNA from the nuclear polyhedrosis viruses of Autographa californica (AcM NPV) and Rachiplusia ou (RoM NPV) were found to be infectious in TN-368 cells employing the calcium phosphate precipitation technique (F.L. Graham and A.J. van der Eb, Virology, 52, 456-467, 1973). Transfection with AcMNPV produced 3600 PFU/microgram DNA compared to 2900 PFU/microgram DNA with RoMNPV. Of eight baculovirus DNAs tested, only AcMNPV DNA and RoMNPV DNA could transfect TN-368 cells. The in vitro host range of AcMNPV DNA was determined to be the same as AcMNPV extracellular virus. AcMNPV Form 1 DNA was fourfold more infectious in TN-368 cells than Form II DNA.