title: Deep UV autofluorescence microscopy for cell biology and tissue histology.
abstract: BACKGROUND
  Autofluorescence spectroscopy is a powerful tool for molecular histology and for following metabolic processes in biological samples as it does not require labelling. However, at the microscopic scale, it is mostly limited to visible and near infrared excitation of the samples. Several interesting and naturally occurring fluorophores can be excited in the UV and deep UV (DUV), but cannot be monitored in cellulo nor in vivo due to a lack of available microscopic instruments working in this wavelength range. To fulfil this need, we have developed a synchrotron-coupled DUV microspectrofluorimeter which is operational since 2010. An extended selection of endogenous autofluorescent probes that can be excited in DUV, including their spectral characteristics, is presented. The distribution of the probes in various biological samples, including cultured cells, soft tissues, bone sections and maize stems, is shown to illustrate the possibilities offered by this system. In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology.
  
  
  RESULTS
  To fulfil this need, we have developed a synchrotron-coupled DUV microspectrofluorimeter which is operational since 2010. An extended selection of endogenous autofluorescent probes that can be excited in DUV, including their spectral characteristics, is presented. The distribution of the probes in various biological samples, including cultured cells, soft tissues, bone sections and maize stems, is shown to illustrate the possibilities offered by this system. In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology.
  
  
  CONCLUSIONS
  In this work we demonstrate that DUV autofluorescence is a powerful tool for tissue histology and cell biology.
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, Gif sur Yvette, France. jamme@synchrotron-soleil.fr
authors.forename: Frédéric
authors.initials: F
authors.lastname: Jamme
authors.forename: Slavka
authors.initials: S
authors.lastname: Kascakova
authors.forename: Sandrine
authors.initials: S
authors.lastname: Villette
authors.forename: Fatma
authors.initials: F
authors.lastname: Allouche
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pallu
authors.forename: Valérie
authors.initials: V
authors.lastname: Rouam
authors.forename: Matthieu
authors.initials: M
authors.lastname: Réfrégiers
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000166:cytology*; D003585:Cell Biology / Q000295:instrumentation; D003584:Cytological Techniques; D006367:HeLa Cells; D006652:Histological Techniques; D006653:Histology / Q000295:instrumentation; D006801:Humans; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D010011:Osteocytes / Q000166:cytology; D051381:Rats; D013234:Stem Cells / Q000166:cytology*; D014466:Ultraviolet Rays; D003313:Zea mays / Q000166:cytology*
keywords: Autofluorescence; DUV; Microspectroscopy; Synchrotron; UV