BIODAI is widely used to detect Annexin -PI apoptotic cells for 5min, and the specific steps are as follows: 1) Suspended cells: 300g, centrifuged at 4℃ for 5min, and collected cells. Adherent cells: digested with trypsin without EDTA, 300g, centrifuged at 4℃ for 5min minutes, and cells were collected. Pancreatic enzyme digestion time should not be too long (see precautions) to prevent false positive. 2) Wash the cells with precooled PBS twice, and centrifuge at 300g and 4℃ for 5 minutes each time to collect 1-5× 105 cells. Note: When cleaning cells, try to avoid damaging cells. 3) Add 100? L 1× binding buffer resuspended cells. 4) add 5? Lan Xin v-FITC and 5? L PI, stir gently. 5) Avoid light and react at room temperature 10 min. 6) Join 400? L 1 x combined with buffer, mixed evenly, and the sample was detected by flow cytometry or fluorescence microscope within 1 hour.