@article{EndesfelderMalkuschFlottmannetal.2011,
  author    = {Endesfelder, Ulrike and Malkusch, Sebastian and Flottmann, Benjamin and Mondry, Justine and Liguzinski, Piotr and Verveer, Peter J. and Heilemann, Mike},
  title     = {Chemically Induced Photoswitching of Fluorescent Probes - A General Concept for Super-Resolution Microscopy},
  series = {Molecules},
  volume    = {16},
  journal   = {Molecules},
  number    = {4},
  doi       = {10.3390/molecules16043106},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134080},
  pages     = {3106-3118},
  year      = {2011},
  abstract  = {We review fluorescent probes that can be photoswitched or photoactivated and are suited for single-molecule localization based super-resolution microscopy. We exploit the underlying photochemical mechanisms that allow photoswitching of many synthetic organic fluorophores in the presence of reducing agents, and study the impact of these on the photoswitching properties of various photoactivatable or photoconvertible fluorescent proteins. We have identified mEos2 as a fluorescent protein that exhibits reversible photoswitching under various imaging buffer conditions and present strategies to characterize reversible photoswitching. Finally, we discuss opportunities to combine fluorescent proteins with organic fluorophores for dual-color photoswitching microscopy.},
  language  = {en}
}
@article{EckhardtAndersMuranyietal.2011,
  author    = {Eckhardt, Manon and Anders, Maria and Muranyi, Walter and Heilemann, Mike and Krijnse-Locker, Jacomine and M{\"u}ller, Barbara},
  title     = {A SNAP-Tagged Derivative of HIV-1-A Versatile Tool to Study Virus-Cell Interactions},
  series = {PLoS ONE},
  volume    = {6},
  journal   = {PLoS ONE},
  number    = {7},
  doi       = {10.1371/journal.pone.0022007},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133534},
  pages     = {e22007},
  year      = {2011},
  abstract  = {Fluorescently labeled human immunodeficiency virus (HIV) derivatives, combined with the use of advanced fluorescence microscopy techniques, allow the direct visualization of dynamic events and individual steps in the viral life cycle. HIV proteins tagged with fluorescent proteins (FPs) have been successfully used for live-cell imaging analyses of HIV-cell interactions. However, FPs display limitations with respect to their physicochemical properties, and their maturation kinetics. Furthermore, several independent FP-tagged constructs have to be cloned and characterized in order to obtain spectral variations suitable for multi-color imaging setups. In contrast, the so-called SNAP-tag represents a genetically encoded non-fluorescent tag which mediates specific covalent coupling to fluorescent substrate molecules in a self-labeling reaction. Fusion of the SNAP-tag to the protein of interest allows specific labeling of the fusion protein with a variety of synthetic dyes, thereby offering enhanced flexibility for fluorescence imaging approaches. Here we describe the construction and characterization of the HIV derivative HIV(SNAP), which carries the SNAP-tag as an additional domain within the viral structural polyprotein Gag. Introduction of the tag close to the C-terminus of the matrix domain of Gag did not interfere with particle assembly, release or proteolytic virus maturation. The modified virions were infectious and could be propagated in tissue culture, albeit with reduced replication capacity. Insertion of the SNAP domain within Gag allowed specific staining of the viral polyprotein in the context of virus producing cells using a SNAP reactive dye as well as the visualization of individual virions and viral budding sites by stochastic optical reconstruction microscopy. Thus, HIV(SNAP) represents a versatile tool which expands the possibilities for the analysis of HIV-cell interactions using live cell imaging and sub-diffraction fluorescence microscopy.},
  language  = {en}
}
@article{WolterEndesfelderLindeetal.2011,
  author    = {Wolter, Steve and Endesfelder, Ulrike and Linde, Sebastian van de and Heilemann, Mike and Sauer, Markus},
  title     = {Measuring localization performance of super-resolution algorithms on very active samples},
  series = {Optics Express},
  journal   = {Optics Express},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85936},
  year      = {2011},
  abstract  = {Super-resolution fluorescence imaging based on inglemolecule localization relies critically on the availability of efficient processing algorithms to distinguish, identify, and localize emissions of single fluorophores. In multiple current applications, such as threedimensional, time-resolved or cluster imaging, high densities of fluorophore emissions are common. Here, we provide an analytic tool to test the performance and quality of localization microscopy algorithms and demonstrate that common algorithms encounter difficulties for samples with high fluorophore density. We demonstrate that, for typical single-molecule localization microscopy methods such as dSTORM and the commonly used rapidSTORM scheme, computational precision limits the acceptable density of concurrently active fluorophores to 0.6 per square micrometer and that the number of successfully localized fluorophores per frame is limited to 0.2 per square micrometer.},
  language  = {en}
}
@article{EndesfelderMalkuschFlottmannetal.2011,
  author    = {Endesfelder, Ulrike and Malkusch, Sebastian and Flottmann, Benjamin and Mondry, Justine and Liguzinski, Piotr and Verveer, Peter J. and Heilemann, Mike},
  title     = {Chemically Induced Photoswitching of Fluorescent Probes - A General Concept for Super-Resolution Microscopy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74896},
  year      = {2011},
  abstract  = {We review fluorescent probes that can be photoswitched or photoactivated and are suited for single-molecule localization based super-resolution microscopy. We exploit the underlying photochemical mechanisms that allow photoswitching of many synthetic organic fluorophores in the presence of reducing agents, and study the impact of these on the photoswitching properties of various photoactivatable or photoconvertible fluorescent proteins. We have identified mEos2 as a fluorescent protein that exhibits reversible photoswitching under various imaging buffer conditions and present strategies to characterize reversible photoswitching. Finally, we discuss opportunities to combine fluorescent proteins with organic fluorophores for dual-color photoswitching microscopy.},
  subject      = {Super-Resolution Microscopy},
  language  = {en}
}