12 well transwell plates 8.0 μm pore filters

The analysis of cell invasion ability was performed with 12‐well transwell plates (8.0‐μm pore filters) (Corning, NY). After coating with matrigel basement membrane matrix, 1 × 10⁵ cells were seeded into the upper chamber in a serum‐free DMEM medium. The bottom chamber was filled with DMEM medium including 10% FBS. Then, it was incubated for 24 h at 37^°C. Then, cells were fixed with 95% ethanol for 20 min and stained with crystal violet for 20 min. The invasive cells on the lower side of the filter were viewed under a light microscope.

The 12-well transwell plates (8.0 μm pore filters) (Corning, NY) were used to determine the invasion and migration of LLC cells. For cell migration assay, the LLC cells (1 × 10⁵) were seeded in the upper chamber of the transwell plate with serum-free DMEM medium. The DMEM medium with 10% FBS was added into the bottom chamber. The plate was incubated at 37 °C for 24 h. Then, the membrane of transwell was took off, fixed with 95% ethanol and stained with crystal violet staining. The cells got through the membrane were calculated under the microscope. For cell invasion assay, firstly, the membrane of 12-well transwell plate was coated with matrigel. Then the LLC cells were seeded in the upper chamber. The following protocol was the same with the migration assay.