Hello, I'm trying to find a less toxic stain for Hut78 cells used for imaging on Zeiss 880 confocal microscope within a range similar to that of CFSE. I tried Viafluor SE Cell Proliferation dye in 488 as the 405nm stain works well for the cells which are cocultured with the Hut78, but after 3 days the Hut78 cells are all dead when alone in a well. Please let me know any recommendations, thank you!