Quantification of Rev-VNP circadian expression, cell displacement and nucleus size in NIH3T3 fibroblasts using CGE. NIH3T3 Rev-VNP cells were synchronized using dexamethasone, and time-lapse microscopy of VNP fluorescence in the nuclei of individual cells was performed. Images were taken every 30 min for three consecutive days. The movies were created from the time-lapse series using Leica AS MDW software and analyzed using CGE ImageJ plug-in. A. Left panels: an individual nucleus tracked during 33 hours. Graph on the right: blue curve corresponds to Rev-VNP fluorescence level per nucleus; red curve reflects nucleus size over the time. B. Time lapse microscopy of Rev-VNP fluorescence in three individual nuclei over 72 hours. For each nucleus, the fluorescence intensity over the nucleus, nucleus size, nucleus displacement and variation of direction, were quantified and plotted against time. Time of cell division is marked when applicable (see A.).