Cell invasion was assessed with Transwell assay
SKOV3 cells were seeded in petri dishes and administered with media, 2.5% sevoflurane, or 4 μg/mL propofol for 2 hours. After administration, cancer cells were mixed with FBS-free media and seeded in the upper chamber of the Transwell assay kit, which was pre-embedded with Corning Matrigel matrix (Corning, New York, USA). The FBS-enriched media was placed into the lower chamber of the Transwell assay kit. After incubated at 37°C for 24 hours, the upper chamber was inserted in the 70% methanol (ThermoFisher, Paisley, UK) for 30 minutes. The cancer cells on the upper chamber were dyed with 0.1% crystal violet (Sigma-Aldrich, Dorset, UK) for 15 minutes and washed to get away the leftover dye. The cells on the upper membrane of the upper chamber were removed. The cells on the bottom membrane of it were regarded as invasive cells and detected by a microscope. The number of invasive cells was counted with Fiji (ImageJ 2.0) software (National Institutes of Health, Bethesda, Maryland, USA).