Phase imaging with a high-resolution wavefront sensor is a useful setup for biological imaging. Our setup is based on a quadriwave lateral shearing interferometer mounted on a commercial non-modified transmission white-light microscope. That allows us to make simultaneous measurement in both quantitative transmission phase and fluorescence imaging. We propose here to study co-localization between phase and fluorescence on african green monkey kidney COS7 cells. Phase permits an enhanced visualization of the whole cell and intracellular components while the fluorescence allows a complete identification of each component. Post treatments on phase-shift images are proposed and become very interesting for enhanced visualization of small details such as vesicles or mitochondrias.