Fig. 4

MTT reduction and phagocytic assays for BuLIF on M1 cells. A For MTT assay, M1 cells were culture for 24 h with and without BuLIF and BuLIF (0–50 ng/ml). The reduction of MTT was dependent on the dose of BuLIF. Stimulated M1 cells showed high dehydrogenase activity in comparison to control M1 cells, p < 0.05. B For phagocytosis assay, M1 cells were treated for 4 days with and without BuLIF (40 ng/ml) and incubated with fluorescent latex beads for 24 h at 37 °C. Ba, Bb Unstimulated M1 cells were not phagocytic; Bc, Bd M1 cells were phagocytic and engulfed two to three FITC conjugated latex beads. Magnification, × 20