Production of HDV virions. Northern analysis of RNAs from supernatants of Huh7 cells transfected with HDV and/or HBV genome-encoding constructs. Following transfection of Huh7 cells with pSVLD3 alone (lanes 1, 4, 7, and 10), pGEM4ayw.2x alone (lanes 2, 5, 8, and 11), or both constructs (lanes 3, 6, 9, and 12), culture media were collected on day 3 (lanes 1 to 3), day 6 (lanes 4 to 6), and day 9 (lanes 7 to 9) and processed for HDV RNA analysis, as described in Materials and Methods. Lanes 10 to 12 contain RNA isolated from the underlying cells at day 9. Arrows indicate sizes of circular HDV genomic RNA.