LUHMES Cell Viability and Cytotoxicity Assays

Cell viability was quantified by the reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) by the LUHMES cells for 1 h in the cell culture incubator. Total medium containing MTT was removed, and the cell culture dishes were frozen at −80 °C for at least an hour to stop the reaction. After thawing at room temperature, the dye was dissolved in 80 µl of DMSO, and the absorbance was measured at 570 nm with a reference filter at 630 nm with a FLUOStar OPTIMA reader (BMG Labtech, Ortenberg, Germany) as described^{29 (link)}.
Additionally, to analyse the cell viability at different time intervals, we also measured the lactate dehydrogenase (LDH) release in the media after 24, 48, and 72 h of viral infections by using commercially available LDH-Glo^TM Cytotoxicity assay (J2380).