title: Optimal ultraviolet wavelength for in vivo photoacoustic imaging of cell nuclei.
abstract: In order to image noninvasively cell nuclei in vivo without staining, we have developed ultraviolet photoacoustic microscopy (UV-PAM), in which ultraviolet light excites nucleic acids in cell nuclei to produce photoacoustic waves. Equipped with a tunable laser system, the UV-PAM was applied to in vivo imaging of cell nuclei in small animals. We found that 250 nm was the optimal wavelength for in vivo photoacoustic imaging of cell nuclei. The optimal wavelength enables UV-PAM to image cell nuclei using as little as 2 nJ laser pulse energy. Besides the optimal wavelength, application of a wavelength between 245 and 275 nm can produce in vivo images of cell nuclei with specific, positive, and high optical contrast.
authors.affiliation: Washington University in St. Louis, Department of Biomedical Engineering, St. Louis, MO 63130, USA.
authors.forename: Da-Kang
authors.initials: DK
authors.lastname: Yao
authors.forename: Ruimin
authors.initials: R
authors.lastname: Chen
authors.forename: Konstantin
authors.initials: K
authors.lastname: Maslov
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 / Q000000981:diagnostic imaging*; D002478:Cells, Cultured; D005260:Female; D007089:Image Enhancement / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D033401:Microscopy, Acoustic / Q000379:methods*; D061088:Photoacoustic Techniques / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays