Transwell Cell Migration and Invasion Assay

Cell migration and invasion assays were performed with 8-μm pore Transwell chambers (Corning, NY, USA) as previously described [23 (link)]. Overall, 5 × 10⁴ or 8 × 10⁴ cells in 200 μl serum-free medium were seeded in the upper chamber coated with or without Matrigel for migration or invasion assays, respectively. The lower chambers were filled with 600 μL medium with 10% FBS for migration or with 20% FBS for invasion. After 24–36 h, the cells on the bottom surface of the membrane were fixed with 95% ethanol and stained with 0.1% crystal violet. Five random fields (× 200) were counted using a microscope to assess cell migration and invasion.