For example, water have RI 1.33, lipids and proteins around 1.40 – 1.45.[19] As result the light is scattered on its path through the tissue, which leads to decrease in resolution or even to disappearance of signal in samples thicker than a few tens of micrometers. Series of steps including dehydration and delipidation of tissue and its subsequent incubation and imaging in medium with RI similar to imaged structures therefore decrease the scattering of light and leads to transparent sample.[20][21]