RAW 264.7 cells were loaded with different concentrations of FURA2-AM (ab120873) in a pluronic F-127/DMSO/ HBSS solution for 30 minutes at room temperature and in the dark. After performing two washes with pre-warmed HBSS the cells were further incubated for 30 minutes at 37°C in the dark. Finally, washes with pre-warmed HBSS were performed and the live cells were imaged.