In order to further exploit RhQ for long-term tracing of VDPs in whole cells, we obtained the time-lapse images up to 90 min. Herein, the commercially available probe for mitochondria (Mitotracker Green) was used for the colocalization assay. With increasing time, the intracellular fluorescence signal from RhQ gradually appeared and increased. Through merging of the fluorescence signal from the RhQ labelled channel (red) and Mitotracker Green labelled channel (green), we could clearly observe that the fluorescence signal of RhQ localized in the mitochondria (Figure , and S12), indicating that the most abundant protein vicinal dithiols are found in the mitochondria. Movies obtained from the time-lapse images of the overlay channel further confirm that RhQ could capture the dynamics of VDPs in whole cells within 90 min (Movie S3.1a and S3.2a).