4.17. Transwell-Migration and Invasion Assay

Cell migration and invasion were assessed with modified Boyden chamber (Becton Dickinson Labware) assays. Briefly, cells, approximately 1.0 × 10⁵, were plated into the upper chamber of a polycarbonate Transwell filter chamber, with or without matrigel (Corning, NY, USA). After 24 h, cells that did not migrate were removed from the top side of the inserts with a cotton swab. Cells that migrated to or invaded the underside of the inserts were fixed in 4% paraformaldehyde, stained with crystal violet, and the migratory cells were counted under a light microscope. Cells were counted in 5 random fields per insert. Three independent experiments were carried out [71].