title: Protein expression guided chemical profiling of living cells by the simultaneous observation of Raman scattering and anti-Stokes fluorescence emission.
abstract: Our current understanding of molecular biology provides a clear picture of how the genome, transcriptome and proteome regulate each other, but how the chemical environment of the cell plays a role in cellular regulation remains much to be studied. Here we show an imaging method using hybrid fluorescence-Raman microscopy that measures the chemical micro-environment associated with protein expression patterns in a living cell. Simultaneous detection of fluorescence and Raman signals, realised by spectrally separating the two modes through the single photon anti-Stokes fluorescence emission of fluorescent proteins, enables the accurate correlation of the chemical fingerprint of a specimen to its physiological state. Subsequent experiments revealed the slight chemical differences that enabled the chemical profiling of mouse embryonic stem cells with and without Oct4 expression. Furthermore, using the fluorescent probe as localisation guide, we successfully analysed the detailed chemical content of cell nucleus and Golgi body. The technique can be further applied to a wide range of biomedical studies for the better understanding of chemical events during biological processes.
authors.affiliation: Department of Chemistry, the University of Tokyo, Tokyo, Japan.|Department of Applied Physics, Osaka University, Osaka, Japan.
authors.forename: Liang-da
authors.initials: LD
authors.lastname: Chiu
authors.affiliation: Quantitative Biology Center, RIKEN, Osaka, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Ichimura
authors.affiliation: Department of Applied Physics, Osaka University, Osaka, Japan.
authors.forename: Takumasa
authors.initials: T
authors.lastname: Sekiya
authors.affiliation: Immunology Frontier Research Center, Osaka University, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Machiyama
authors.affiliation: Quantitative Biology Center, RIKEN, Osaka, Japan.
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Quantitative Biology Center, RIKEN, Osaka, Japan.|Immunology Frontier Research Center, Osaka University, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Department of Chemistry, the University of Tokyo, Tokyo, Japan.
authors.forename: Takeaki
authors.initials: T
authors.lastname: Ozawa
authors.affiliation: Department of Applied Physics, Osaka University, Osaka, Japan.
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Fujita
mesh_terms: D000818:Animals; D015415:Biomarkers; D015870:Gene Expression; D017930:Genes, Reporter; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D055432:Metabolomics / Q000379:methods; D051379:Mice; D008856:Microscopy, Fluorescence; D057054:Molecular Imaging; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D011993:Recombinant Fusion Proteins; D013059:Spectrum Analysis, Raman; D013234:Stem Cells / Q000378:metabolism
chemical_list: D015415:Biomarkers; D008164:Luminescent Proteins; D050814:Octamer Transcription Factor-3; D011993:Recombinant Fusion Proteins