Dna fragmentation detection kit

The TUNEL assay was performed to detect in situ apoptosis in the tumor xenograft using a DNA Fragmentation Detection Kit (Beyotime) according to the instructions from the manufacturer. The dewaxed sections were incubated with DNase-free protease K (20 μg/mL, Beyotime) in 10 mM Tris (pH 7.5) at 37 °C for 20 min and washed with PBS. Then, sections were stained with the TUNEL staining mixture at 37 °C for 1 h in the dark, followed by a PBS wash and counterstaining with 4′,6-diamidino-2-phenylindole (DAPI). The stained sections were observed under a fluorescence microscope. Nuclei were stained blue, and apoptotic cells were stained red.

TUNEL assay was performed using a DNA Fragmentation Detection Kit (Beyotime Biotech), as described previously [57 (link)]. Briefly, cells were treated with α-solanine for 18 h, fixed with 4% PFA for 30 min, rinsed with PBS, and permeabilized with Triton X-100 (0.1%) on ice. Then, cells were stained with TUNEL staining mixture for 1 h at 37 °C in the dark and counterstained with 4’, 6’diamidino-2-phenylindole (DAPI) for 5 min at room temperature. The apoptotic cells were observed using a fluorescence microscope (Olympus, IX73P1F, Japan). Cells from five random fields were counted using ImageJ software.