2.3. Cell Viability Assay

For detection of DCQD cytotoxicity and cell viability, cell counting kit‐8 (CCK‐8) assay was applied in this study. Procedures were as follows. Firstly, AR42J cells were incubated in each well of a 96-well plate at a density of 4 × 10³ cells/well and grown for 12 hours. Thereafter, cells were pretreated with different concentrations of DCQD (C, C/2, C/3, C/4, C/5, C/10) for 2 h. Secondly, the CCK‐8 solution (Signalway Antibody LLC, Maryland, USA) was added to each well. After incubation for 1 h, absorbance for detecting cell viability was read at 450 nm on a microplate reader (iMark680; Bio-Rad Laboratories, Inc.) and converted to cell numbers with the standard curve. To observe the morphological change, the cells were observed under an optical microscope (XDS-500C, Peikon, Shanghai).