Real-time background-free selective imaging of fluorescent nanodiamonds in vivo.
Recent developments of imaging techniques have enabled fluorescence microscopy to investigate the localization and dynamics of intracellular substances of interest even at the single-molecule level. However, such sensitive detection is often hampered by autofluorescence arising from endogenous molecules. Those unwanted signals are generally reduced by utilizing differences in either wavelength or fluorescence lifetime; nevertheless, extraction of the signal of interest is often insufficient, particularly for in vivo imaging. Here, we describe a potential method for the selective imaging of nitrogen-vacancy centers (NVCs) in nanodiamonds. This method is based on the property of NVCs that the fluorescence intensity sensitively depends on the ground state spin configuration which can be regulated by electron spin magnetic resonance. Because the NVC fluorescence exhibits neither photobleaching nor photoblinking, this protocol allowed us to conduct long-term tracking of a single nanodiamond in both Caenorhabditis elegans and mice, with excellent imaging contrast even in the presence of strong background autofluorescence.
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
Ryuji
R
Igarashi
Yohsuke
Y
Yoshinari
Hiroaki
H
Yokota
Takuma
T
Sugi
Fuminori
F
Sugihara
Kazuhiro
K
Ikeda
Hitoshi
H
Sumiya
Shigenori
S
Tsuji
Ikue
I
Mori
Hidehito
H
Tochio
Yoshie
Y
Harada
Masahiro
M
Shirakawa
D000818:Animals; D017173:Caenorhabditis elegans; D006367:HeLa Cells; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D058612:Nanodiamonds / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D009584:Nitrogen / Q000737:chemistry; D017785:Photons; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
D058612:Nanodiamonds; D009584:Nitrogen