FIG 2.

Cell viability assay and assessment of S2 cell status. (A) Cell viability assay of S2 cells. (a) Cell viability assay of S2 cells without stimulation. (b and c) Cell viability assays of S2 cells after heat-killed S. eriocheiris (b) and S. eriocheiris (c) inoculation for 0, 12, 24, 36, 48, and 72 h. Different letters indicate significant differences (P < 0.05). The data are means ± the standard deviations (SD) of three independent experiments. (B) S. eriocheiris-infected S2 cells at 0, 12, 24, 36, 48 and 72 h. Apoptotic or necrotic cells were stained red by PI, and normal cells were not stained. Scale bar, 10 μm. (C) S2 cells were stimulated with PBS (left) or S. eriocheiris (right) for 48 h. The apoptotic cells were labeled with FITC-annexin V and PI for 30 min and analyzed by FCM.