Ultraviolet photoacoustic microscopy with tissue clearing for high-contrast histological imaging
Xiufeng Li, Jack C.K. Kot, Victor T. C. Tsang, Claudia T. K. Lo, Bingxin Huang, Ye Tian, Ivy H. M. Wong, Helen H.Y. Cheung, Lei Kang, Atta Cheuk Yan Chang, Terence T. W. Wong
Abstract
Ultraviolet photoacoustic microscopy (UV-PAM) has been investigated to provide label-free and registration-free volumetric histological images for whole organs, offering new insights into complex biological organs. However, because of the high UV absorption of lipids and pigments in tissue, UV-PAM suffers from low image contrast and shallow image depth, hindering its capability for revealing various microstructures in organs. To improve the UV-PAM imaging contrast and imaging depth, here we propose to implement a state-of-the-art optical clearing technique, CUBIC (clear, unobstructed brain/body imaging cocktails and computational analysis), to wash out the lipids and pigments from tissues. Our results show that the UV-PAM imaging contrast and quality can be significantly improved after tissue clearing. With the cleared tissue, multilayers of cell nuclei can also be extracted from time-resolved PA signals. Tissue clearing-enhanced UV-PAM can provide fine details for organ imaging.