A Systematic Analysis of Host Factors Reveals a Med23-Interferon-? Regulatory Axis against Herpes Simplex Virus Type 1 Replication

Griffiths, Samantha J.; Koegl, Manfred; Boutell, Chris; Zenner, Helen L.; Crump, Colin M.; Pica, Francesca; Gonzalez, Orland; Friedel, Caroline C.; Barry, Gerald; Martin, Kim; Craigon, Marie H.; Chen, Rui; Kaza, Lakshmi N.; Fossum, Even; Fazakerley, John K.; Efstathiou, Stacey; Volpi, Antonio; Zimmer, Ralf; Ghazal, Peter; Haas, Jürgen

Cells were transfected as described above, and the cytotoxicity of siRNAs was determined using the CellTiter Blue (CTB, Promega) reagent, which gives a fluorescent or absorbance signal relative to the number of live cells. Briefly, 5 ml CTB was added per well using the Multidrop 384. Plates were incubated at 37uC in a humidified incubator with 5% CO 2 for 2 h before measuring fluorescence (POLARstar OPTIMA plate reader). Readings were normalized to viability of mock-transfected cells, per plate, and mean cell viability over three replicates was calculated. Distribution analysis of cell viability values identified median viability as 60%, and values ,60% were considered cytotoxic.