Fig. 5

Nucleus pulposus (NP) cell viability analysis. a: Comparison of NP cell viability between fresh discs and discs from the EG and CG. Data are expressed as the mean ± SD (n = 4). *: p < 0.05 vs. the CG; #: p < 0.05 vs. fresh discs. b and c: Live and dead cells were visualized using fluorescence microscopy. Viable cells were double stained with DAPI and NBT (red arrow) while dead cells were only stained with DAPI (white arrow). CG: control group; EG: experimental group. Magnification: 200x, scale represents 100 μm