Flow cytometric analysis of RAW264.7 macrophages exposed to B. abortus 2308 and omp10 mutants. RAW264.7 macrophages were suspended with Binding Buffer and treated by Annexin V-FITC and PI at room temperature. A, cells were collected at different time points after infection, cell apoptosis images containing B. abortus. B, percentage of apoptosis at different time points after infection.