2.11. Cell Toxicity Test Using MTT

The cell toxicity test was performed with the procedure suggested by Merck KGaA company [32]. The target A549 cells were divided to 96-well plates (Nunc) with 1 × 10⁴ cells per well and were cultured overnight. In the following day, the medium was removed and replaced with 1 × 10⁴ T or CAR-T cells cultured in the TexMAXS medium containing 300 U/mL IL-2 and T-cell TransAct™. This process was repeated three times. Cells were monitored for an additional 2 days. The survival/death rate was determined by MTT (3-(4,5-Dimethyl-2-thiazolyl)-2.5 diphenyltetrazolium bromide-sigma). The obtained data was then analyzed using the Excel software to determine the cell viability (% Cell viability).

Control sample: the sample had only cells and cell culture medium.

Analytical sample: reagent sample had corresponding concentrations in cell culture medium.

Blank: cell culture medium.