Tissue-clearing techniques have received great attention for volume imaging and for the potential to be applied in optical diagnosis. In principle, tissue clearing is achieved by reducing light scattering through a combination of lipid removal, size change, and matching of the refractive index (RI) between the imaging solution and the tissue. However, the contributions of these major factors in tissue clearing have not been systematically evaluated yet. In this study, we experimentally measured and mathematically calculated the contribution of these factors to the clearing of four organs (brain, liver, kidney, and lung). We found that these factors differentially influence the maximal clearing efficacy of tissues and the diffusivity of materials inside the tissue. We propose that these physical properties of organs can be utilized for the quality control (Q/C) process during tissue clearing, as well as for the monitoring of the pathological changes of tissues.
Bibliographical noteFunding Information:
We greatly appreciate the thoughtful comments from Dr. Jae Ryun Ryu and Hyun Jung Kim, technical support from the members of Sun’s lab, and drawing of the schematic figures by Ye-Jin Son. This research was supported by the Brain Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT (NRF-2018M3C7A1025485, NRF-2016R1A6A3A01009971).
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