2.4. Transwell Migration Assay

Transwell migration assays were performed to determine the effects of OMT on GBM cell migration. U251 and A172 cells (500 cells/well) were seeded into the upper chamber of a polycarbonate transwell plate (8 μm pores size; Corning, USA) in 300 μL of a serum-free medium with OMT, TMZ, or 1% DSMO at the above concentrations. 800 μL of DMEM with 10% FBS was then added to the lower chamber as a chemoattractant. The plate was incubated for 10 hours and nonmigrated cells were removed from the upper surface of the filter with a cotton swab. The cells that migrated to the lower chamber were stained with 0.1% crystal violet for 15 min at room temperature and were then photographed and counted under high magnification.