Biocoat control cell culture inserts

The tumor cell migration and invasion potentials were determined using Transwell^® chambers (8 µm; Corning, Corning, NY, USA, BioCoat Control Cell Culture Inserts and BioCoat Matrigel Invasion Chambers). Three independent experiments were conducted under the same conditions. The upper Boyden chambers, containing serum-free medium, were seeded with 2×10⁵ cells (for migration), while 5×10⁵ cells were seeded in the upper membranes with serum-free medium (for invasion). Subsequently, 600 µl of medium containing 20% FBS was added to the lower chamber. The cells were cultured in a 37°C incubator with 5% CO₂. Twenty-four hours later, the cells were washed 3 times with PBS and fixed in 4% formaldehyde for 10 min. Non-invading cells in the upper chamber (for migration) or on the upper membrane (for invasion) were removed carefully with a cotton swab, and the cells were then washed again 3 times with PBS. The cells that adhered to the lower surface of the upper chamber (for migration) or the upper membrane (for invasion) were stained with 0.1% crystal violet. Ten randomly selected fields of fixed cells at ×200 magnification were captured using the microscope equipped with a digital camera, and the numbers of cells that were stained purple were counted. The numbers of cells in the different groups were statistically analyzed as previously described.