In vitro quantification of gene expression and viral replication by GLV-1h68 in human head and neck squamous cell carcinoma. A. Cell lines were infected with GLV-1h68 at an MOI of 5, and six hours later quantitative β-galactosidase assays were performed. B. Cell lines were infected with GLV-1h68 at an MOI of 1, and 12 hours later coelenterazine was added. Bioluminescence was imaged with a cooled CCD camera and quantified with software analysis. C. Cell lines were exposed to GLV-1h68 at an MOI of 0.1 and incubated for 72 hours. Supernatants were collected and viral titers quantified by plaque assays on confluent CV-1 cells.