*2.3. Cell Viability Assay*

Cell viability was assayed according to a previous study with some modifications [26]. Briefly, activated Jurkat T cells were diluted to 2 × 105 cells/mL using fresh medium, pipetted into 100 μL of the cell dilutions, seeded in a 96-well multiplate, and treated for 36 h with DMM at final concentrations of 0.5, 5, 25, 50, 100, 250, and 500 mg/L. The final acetone concentration of each well was adjusted to the same concentration and less than 0.1%, which exerted no effect on cell viability. A blank group (without pesticide and cells) and a control group (containing cells, equivalent solvent but without pesticide) were included. Cell viability was determined by the Cell Counting Kit-8 (CCK-8), according to the manufacturer's instructions. Absorbance was measured at 450 nm in a ReadMax 500F enzyme-labeled instrument (Shanpu Biotechnology Co., Ltd., Shanghai, China). Cell viability was calculated using Equation (1).

$$\text{Cell viability} = \frac{\text{A}\_{\text{t}} - \text{A}\_{\text{b}}}{\text{A}\_{\text{c}} - \text{A}\_{\text{b}}} \tag{1}$$

where At is the absorbance of the test group, Ab is the absorbance of the blank group, and Ac is the absorbance of the control group. Concentration–response curves were plotted, and the half maximal effective concentration (EC50) values were then calculated using a sigmoidal dose–response curve equation [27].
