In Vitro: Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs). LysoTracker Yellow HCK 123 assay (to quantify GAPDH): 1. Culture EMT6 cells in 8-well cell culture slides. Incubate the cells according to your normal protocol. 2. Add TONS504 per well to make the final concentration at 30 µg/mL.Incubate cells at 37 °C for 4 hours. 3. Add LysoTracker Yellow HCK 123 per well to make the final concentration at 50 μM. Incubate cells at 37 °C, 5% CO2, for 30 minutes. 4. Analyze samples on a confocal laser scanning microscope.