Lee, Szu-YuSzu-YuLeeLai, Yu-HungYu-HungLaiHuang, Kai-ChihKai-ChihHuangYU-HSIANG CHENGTseng, Tzu-FangTzu-FangTsengCHI-KUANG SUN2018-09-102018-09-102015-10-2120452322http://www.scopus.com/inward/record.url?eid=2-s2.0-84944937683&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/392869https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944937683&doi=10.1038%2fsrep15421&partnerID=40&md5=761aca3722a6c2e10394dc63e97c4db7Microscopy based on non-fluorescent absorption dye staining is widely used in various fields of biomedicine for 400 years. Unlike its fluorescent counterpart, non-fluorescent absorption microscopy lacks proper methodologies to realize its in vivo applications with a sub-femtoliter 3D resolution. Regardless of the most advanced high-resolution photoacoustic microscopy, sub-femtoliter spatial resolution is still unattainable, and the imaging speed is relatively slow. In this paper, based on the two-photon photoacoustic mechanism, we demonstrated a in vivo label free laser-scanning photoacoustic imaging modality featuring high frame rates and sub-femtoliter 3D resolution simultaneously, which stands as a perfect solution to 3D high resolution non-fluorescent absorption microscopy. Furthermore, we first demonstrated in vivo label-free two-photon acoustic microscopy on the observation of non-fluorescent melanin distribution within mouse skin.melanin; animal; isolation and purification; metabolism; microscopy; mouse; photoacoustics; procedures; skin; ultrastructure; Animals; Melanins; Mice; Microscopy; Photoacoustic Techniques; Skinjournal article10.1038/srep15421264873632-s2.0-84944937683