Ro5-4864 inhibits Ag-triggered ROS production. Intracellular ROS were measured in BMMCs by flow cytometry using the ROS-sensitive fluorescent dye H2DCFDA. Background fluorescence was determined for 1 min before indicated BDZs or DMSO were added (first arrow) and incubated for 2 min. Cells were then stimulated with 200 ng/ml Ag (second arrow) and the resulting intracellular ROS response was measured for 3 min. Comparable results were obtained with cells from two different cultures.