Use of Optical Clearing Agents in Human Dermis Imaging by Two Photon Microscopy

We investigate the effects of topical application of optical clearing agents (OCA) in two-photon microscopy of ex-vivo human dermis tissue. We demonstrate that the hyperosmotic agents; glycerol, propylene glycol, and glucose in aqueous solution, are effective in improving the penetration depth and enhancing image contrast. We present results of applying the three agents, including the dynamical behaviour of the clarifying effect. Our results show that propylene glycol and glycerol are more effective than glucose in enhancing contrast and, relative to glucose, penetrate three and five times slower, respectively. At suitable concentrations, such agents have the potential to be compatible with living tissue and may possibly enhance in-vivo deep-tissue imaging.