Fig. 3From: Collaborative study of thresholds for mutagens: proposal of a typical protocol for detection of hormetic responses in cytotoxicity testsNumber of cells per well and hormetic expression time. Firstly, different numbers of HeLa S3 cells (2000, 4000, and 6000 cells/well) were treated with EMS for 6 (a), 12 (b), and 24 h (c) two days after inoculation. Secondly, Hela S3 cells (500, 1000, and 2000 cells/well) were treated with EMS for 9 (d), 12 (e), and 15 h (f). CCK-8 (10 μL/well) was added 2 h before OD-450 measurement. Data show OD-450 ratios (Mean ± SD)Back to article page