Quantitative Phase Imaging (QPI) is a new imaging channel that measures the intrinsic properties (dry mass, refractive index) and topography of biological specimens. Phi Optics’ QPI is the fastest and most accurate imaging of live cell and tissue cultures, providing contrast and resolution where regular microscopy fails or kills the specimens. Phi Optics QPI upgrades your existing microscopes to enable 4D non-destructive, quantitative assays on any range of time, with subcellular resolution.