Cell counting kit 8 (cck8)

The cell viability was measured by the Cell Counting kit-8 (CCK8) (Mei5bio, Beijing, China) assay following the instructions mentioned. The CNOT2 -KO and WT Vero cells were seeded to 96-well plates and infected with or without PEDV for 1 h at 0.01 MOI. Subsequently, the cells were washed three times with PBS and incubated for 36 h, then the cultured supernatant in each well was replaced with 110 µL DMEM containing 9.09% CCK-8 reagent, followed by culturing in the dark for 4 h. After gentle shaking, the optical density 450 (OD450) was measured by a microplate reader. Cell viability value was calculated according to the equation: the cell viability value = (As − Ab) ÷ (Ac − Ab) × 100%, where, As: after incubation with CCK-8 solution, the OD450 values of PEDV infection; Ab: after incubation with CCK-8 solution, the OD450 values of PEDV infection wells without cells; Ac: after incubation with CCK-8 solution, the OD450 values of un-infection wells.

Carboxymethyl chitosan (CMCS) was purchased from Shanghai Ryon Biological Technology CO., Ltd. (Shanghai, China). Silk sericin (SS) was from Langzhong Silkworm Breeding Farm of Sichuan Province (Sichuan, China). Sodium chloride was purchased from Aladdin Biotech CO., Ltd. (Shanghai, China). Potassium bromide was purchased from Sango Biotech Co., Ltd. (Shanghai, China). Bradford assay kit was purchased from Beyotime Biotechnology Co., Ltd. (Shanghai, China). Sodium hydroxide was purchased from Jinshen Chemical Test Co., Ltd. (Chengdu, China). Hydrochloric acid was purchased from Chuandong Chemical Co., Ltd. (Chongqing, China). Cell Counting Kit-8 (CCK-8) was purchased from Mei5 Biotechnology Co., Ltd. (Beijing, China). Trypan blue was purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). The filter membrane with a pore size of 0.22 μm was purchased from Jiangsu Green Union Science Instrument Co., Ltd. (Jiangsu, China). All chemicals were of analytical grade and were used without further purification. Deionized water was obtained from a Milli-Q Direct-8 purification system (resistivity >18 MΩ·cm, Millipore Inc., Boston, MA, USA) onsite and was used in all experiments.

Cell viability was evaluated by CCK8 assay. The transfected CRC cells (LOVO and Caco-2) were seeded at a density of 2×10³ cells/well in 96-well plates and incubated for 0, 24, 48, and 72 h. Subsequently, 10 μL CCK8 (Mei5 Biotechnology Co., Ltd., China) was added to each well and incubated for another hour at 37°C. Absorbance values at 450 nM were measured using a microplate reader (Thermo scientific, USA). Experiments were repeated three times.