title: In vivo label-free photoacoustic microscopy of cell nuclei by excitation of DNA and RNA.
abstract: Imaging of cell nuclei plays a critical role in cancer diagnosis and prognosis. To image noninvasively cell nuclei in vivo without staining, we developed UV photoacoustic microscopy (UV-PAM), in which 266 nm wavelength UV light excites unlabeled DNA and RNA in cell nuclei to produce photoacoustic waves. We applied UV-PAM to ex vivo imaging of cell nuclei in a mouse lip and a mouse small intestine and to in vivo imaging of the cell nuclei in the mouse skin. The UV-PAM images of unstained cell nuclei match the optical micrographs of the histologically stained cell nuclei. Given intrinsic optical contrast and high spatial resolution, in vivo label-free UV-PAM has potential for unique biological and clinical application.
authors.affiliation: Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, USA.
authors.forename: Da-Kang
authors.initials: DK
authors.lastname: Yao
authors.forename: Konstantin
authors.initials: K
authors.lastname: Maslov
authors.forename: Kirk K
authors.initials: KK
authors.lastname: Shung
authors.forename: Qifa
authors.initials: Q
authors.lastname: Zhou
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism* / Q000528:radiation effects*; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D008027:Light; D051379:Mice; D033401:Microscopy, Acoustic / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D012313:RNA / Q000032:analysis / Q000737:chemistry*
chemical_list: D012313:RNA; D004247:DNA