Recent advances in optical microscopy enable the visualization and quantification of biol. processes within live cells. To a great extent, these imaging techniques remain limited by the phys. properties of the chem. probes that are used as fluorescent tags, detectors and actuators. At the same time, the quantification of concns. in the intracellular medium is not trivial, but a few approaches that employ optical microscopy have been developed. Herein, we highlight a few examples of how a combination of novel chem. probes and microscopy methods could be used to bring a much-needed quant. dimension to the field of biol. imaging.