Scratch Assay for Cell Migration

The scratch assay was used to examine the migration of drug-insensitive, DMSO-control, and dabrafenib-insensitive HT-29 cell lines. A 24-well plate containing growth was seeded with an equal number of cells per cell line group (4 × 10⁵/well). After the cells had reached approximately 80% confluence, they were treated for 2 h with 2 g/ml Mitomycin (Serva, VWR International). Scratches were created with a 200 μl pipette tip, and the cells were washed three times to remove debris. DMSO control HT-29 cells were treated with DMSO, while dabrafenib-insensitive HT-29 cells with dabrafenib and fresh growth medium was given to the initial control cells. Cell migration was monitored every 4 h using a Nikon Eclipse Ti2e microscope. The area of closure was calculated via ImageJ.