title: Second harmonic imaging of chloroplasts using the two-photon laser scanning microscope.
abstract: BACKGROUND
  Second harmonic information reveals information about the structure of spatially oriented structures with an asymmetry. We study the second harmonic images of the grana and intergranal parts of chloroplasts in the leaves of the shade moss Plagiomnium affine.
  
  
  RESULTS
  A two-photon microscope with blocking filters to suppress fluorescence generated both forward and backward second harmonic illumination to be captured. In the starch free chloroplasts of the single cell layered laminae strong second harmonic generation (SHG) from the granal regions was emitted. Upon illumination the chloroplasts changed their orientation affecting the SHG signal. Chloroplast is reoriented upon illumination.
  
  
  CONCLUSIONS
  SHG signals were successfully obtained from the grana without any possible confusion from SHG starch grains due to their absence.
authors.affiliation: Institute of Physical Biology, University of South Bohemia, Nove Hrady 37333, Czech Republic. maalidph@yahoo.co.uk
authors.forename: Ali Hussain
authors.initials: AH
authors.lastname: Reshak
authors.forename: Vassilios
authors.initials: V
authors.lastname: Sarafis
authors.forename: Rainer
authors.initials: R
authors.lastname: Heintzmann
mesh_terms: D001718:Birefringence; D019068:Bryopsida / Q000648:ultrastructure; D005453:Fluorescence; D008029:Lighting; D018613:Microscopy, Confocal / Q000295:instrumentation*; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation*; D017785:Photons; D013213:Starch / Q000648:ultrastructure; D020524:Thylakoids / Q000648:ultrastructure*; D013997:Time Factors
chemical_list: D013213:Starch