TUNEL assay for assessing cell apoptosis in granulation tissue postsurgery
The granulation tissue was prepared for apoptosis detection by fixing it, embedding in paraffin, and sectioning and dewaxing with xylene. It was then digested with trypsin, incubated with the TUNEL reaction solution at 37°C for 1 h, then incubated with peroxidase antibody at 37°C for 30 min; diamine benzidine (DAB) was added dropwise, the sample sections were incubated at room temperature for 30 min, then sealed and dried. The sample sections were then immersed in hematoxylin staining solution for nuclear staining for 5 min. The apoptosis rate was determined under a microscope by counting the cell nuclei stained with brownish‐yellow particles as apoptotic positive cells and the apoptosis rate (%) was calculated—apoptosis rate = (number of positive cells/total number of cells) × 100%.