You are here:Home / News / Seminars / Friday, October 6th | Prof. Christopher Cremer : Super-resolution light microscopy of nuclear genome nanostructure

Friday, October 6th | Prof. Christopher Cremer : Super-resolution light microscopy of nuclear genome nanostructure

2017 IBP Seminar Series
Friday, October 6th | Prof. Christopher Cremer : Super-resolution light microscopy of nuclear genome nanostructure
When Oct 06, 2017
from 02:30 PM to 03:30 PM
Where CNR Conference Room
Contact Name
Contact Phone 081/6132722
Add event to calendarvCal

Prof. Christopher Cremer

Institute of Molecular Biology (IMB), D-55128 Mainz, Germany

will present :

Super-resolution light microscopy of nuclear genome nanostructure

A major challenge in the Biosciences is to link the knowledge gained by molecular methods to cellular nanostructure. Until recently, however, “molecular optics” (MO) approaches at the individual cell level using far field light microscopy were substantially  limited by the conventional resolution of about 200 nm in the object plane and 600 nm along the optical axis (“Abbe/Rayleigh-limit”). These limits have been overcome by various super-resolution fluorescence microscopy (SRM) methods, such as Stimulated Emission Depletion (STED), Photoactivated Localization Microscopy (PALM), Structured Illumination Microscopy (SIM), or Stochastic Optical Reconstruction Microscopy (STORM)1. Prof. Cremer will report on a complementary SRM approach for Molecular Optics at the single cell/single molecule level, Spectral Precision Distance/Position Determination Microscopy (SPDM). SPDM, a variant of localization microscopy, makes use of conventional fluorescent proteins or single standard organic fluorophores in combination with standard (or only slightly modified) specimen preparation conditions, allowing to use the same laser frequency for both photoswitching and fluorescence read out2. As an example for the application of this SRM-MO approach, results on nuclear nanostructure elucidation will be presented. Presently, this approach allows to optically resolve nuclear structures in individual mammalian cells down to few tens of nanometer, and to perform quantitative MO analyses of individual small chromatin domains; of the nanoscale distribution of DNA, nascent DNA, histones, chromatin remodeling proteins, as well as transcription, splicing and repair related factors. Novel methodological developments involve a variant of binding activated localization microscopy (BALM)3 to study the three dimensional nanostructure of the nuclear genome using 3D-SPDM. The experimental results support recent models of functional nuclear structure4. As a translational application, using dual-color SPDM, it became possible to monitor in mouse myocardial cells quantitatively the effects of ischemia conditions on the chromatin  nanostructure5. These novel SRM-MO approaches open an avenue to study the molecular landscape directly on the individual cell level at unprecedented resolution.  

1-    C. Cremer, B.R. Masters (2013) Resolution enhancement techniques in microscopy.Eur. Phys. J. H, Eur. Phys. J. H 38: 281–344. 

2-     C. Cremer et al. (2011) Super-resolution Imaging of Biological Nanostructures by Spectral Precision Distance Microscopy (SPDM), Biotechnology Journal 6: 1037 – 1051. 

3-     A. Szczurek et al. (2017) Imaging chromatin nanostructure with binding-activated localisation microscopy based on DNA structure fluctuations. Nucleic Acids Research. doi: 10.1093/nar/gkw1301. 

4-     T. Cremer et al.  (2015) The 4D nucleome: Evidence for a dynamic nuclear landscape based on coaligned active and inactive nuclear  compartments. FEBS LettersFEBS Letters 589: 2931–2943. 

5-     I. Kirmes et al. (2015) A transient ischemic environment induces reversible compaction of chromatin. Genome Biology 16:246.

Filed under: ,