Bacterial viability assays were performed using a Live/Dead BacLight bacterial viability kit (BacLight; Molecular Probes) as previously described.6 (link),21 105 CFU/mL of stained bacteria were incubated with RNase 7, human RNase 6, or mouse RNase 6. Changes in fluorescent intensity were measured using the Spectramax M2 multimode microplate reader (Molecular Devices, Sunnyvale, CA).6 (link),21 These results were compared with a standard curve that was generated using increasing concentrations of live:dead bacteria.