Tunel apoptosis detection kit

Tunel staining using the TUNEL Apoptosis Detection Kit (Wanlei bio, Shenyang, China) was performed according to the manufacturer’s instructions. The paraffinized sections were dewaxed to water and rinsed with phosphate buffer saline (PBS) three times. Then, the tissue sections underwent heat-induced epitope retrieval in citrate buffer followed by a cooling-down period. Next, the paraffin sections were rinsed with PBS and added a tunel assay solution and then incubated at 37°C in the dark for 90 min. Sections were then rinsed with PBS and counterstained with 4’,6-diamidino-2-phenylindole (DAPI) for nuclear labeling. Finally, the anti-fluorescence quencher (Solarbio, Beijing, China) was used to seal the sections. The staining results were observed under a fluorescent microscope (DS-U3, Nikon, Japan), in which tunel-positive expression was recognized by green fluorescence, while DAPI-positive was blue. The apoptotic index’s final calculation was reached according to the following formula: apoptotic index=tunel positive cells/DAPI positive cells (n = 5).

TUNEL assay was performed to detect the apoptotic cells after 3 days in culture using the TdT-FragEL DNA Fragmentation Detection Kit (QIA33, Merck, Darmstadt, Germany) according to the manufacturer’s instructions. Apoptosis of tissue samples was evaluated using another TUNEL apoptosis detection kit (DAB type, Wanlei Biotechnology). TUNEL-positive cells were counted, and the apoptotic rate was calculated as follows: positive cells / (positive cells + negative cells) × 100%.