I have a 2000 frame, 2 channel stack of elongating cells. I need to measure fluorescent intensity at the tip of a given cell. I want to assign a ROI for the first and last frame, and use ImageJ to automatically determine the ROI position for remaining frames. I think I can use an average growth rate to determine ROI distance moved per frame. An easier option would be to draw a line representing the path for multiple ROIs through the stack, but I’m a newbie and am stuck! Please help.