Abstract
We investigate the effects arising from the topical application of optical clearing agents (OCA) in two photon microscopy imaging of human ex-vivo dermis tissue. We demonstrate that hyperosmotic agents such glycerol, propylene glycol and glucose in aqueous solution are effective in improving penetration depth and enhancing image contrast. We examine the results provided by the three agents, as well as the dynamical behaviour of the clarifying effect. Our results show that propylene glycol and anhydrous glycerol are more effective than glucose in enhancing contrast, also if glucose diffuses three and live times faster, respectively. All results are in agrement with a diffusive model of the agent into the tissue. At suitable concentrations, such agents have the potential to be compatible with living tissue and may possibly enhance in-vivo deep-tissue imaging.