2.6. Cell viability assay

The viability of HGC‐27 or SNU‐1 cells was analyzed using an MTT Cell Proliferation and Cytotoxicity Assay Kit (M1020) from Solarbio (China). HGC‐27 or SNU‐1 cells were cultured routinely for 24, 48, or 72 hours in a 96‐well plate, and then, 90 μl of fresh medium and 10 μl of MTT reagent were added to each well to further culture the cells for 4 hours. Afterward, 110 μl of Formazan solution was added and shaken for 10 minutes. Finally, the absorbance was measured at 490 nm using a microplate absorbance reader (E0228) from Beyotime (China).