2.18.4. [3H]–Thymidine Incorporation (DNA Biosynthesis Assay)

Cells were seeded in 24-well plates at 1 × 10⁵ cells/well with 1 mL of growth medium. After 48 h to subconfluent cells, various concentrations of F1–F3 or PF films and 0.5 mCi of [3H]–thymidine were added. The incubation was continued for 24 h at 37 °C. Cells were rinsed three times with PBS, solubilized with 1 mL of 0.1 mol/L sodium hydroxide containing 1% SDS, then scintillation fluid Ultima Gold XR was added and incorporation of the tracer into DNA was measured in scintillation counter. Values were described as a percent of control [53].