We developed a deep-ultraviolet (UV) microscope capable of imaging cell mitosis and motility at 280 nm for 45 min with minimal UV-induced toxicity, and for 6 h before the onset of visible cell death in cultured human and mouse cells. Combined with computational methods that convert the intensity of each pixel into an estimate of mass, deep-UV microscopy images generate maps of nucleic acid mass, protein mass and fluorescence yield in unlabeled cells.