High-resolution analysis of barrier function

Ann N Y Acad Sci. 2009 May;1165:74-81. doi: 10.1111/j.1749-6632.2009.04047.x.


High-resolution analysis of epithelial barrier function adds substantial information to that provided by conventional transepithelial electrical resistance (TER) measurements. This chapter describes three high-resolution techniques. First, two variants of impedance spectroscopy are delineated. One-path impedance spectroscopy discriminates vertically between serial pathways, namely resistances of the epithelial cell layer and of subepithelial tissues. As a typical application, measurements on human sigmoid colon biopsies from patients suffering from Crohn's disease are reported. Two-path impedance spectroscopy allows to discriminate between trans- and paracellular resistance, and the general principle of this technique is outlined. Second, the conductance scanning technique is presented, which discriminates horizontally between optically distinct parallel pathways over a wide range of spatial resolutions. Using this technique, it was shown that occludin--in contrast to the then prevailing opinion--is not irreplaceable to barrier function. Third, three-dimensional confocal fluorescence imaging for depicting transepithelial transport processes is introduced. Using this method the transepithelial translocation of bacteria which generate focal leaks was discovered.

MeSH terms

  • Animals
  • Cell Line
  • Cell Membrane Permeability
  • Colon, Sigmoid / metabolism
  • Electric Conductivity
  • Electric Impedance
  • Epithelial Cells / physiology*
  • Hemolysin Proteins / metabolism
  • Hemolysin Proteins / ultrastructure
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Microscopy, Confocal
  • Occludin


  • Hemolysin Proteins
  • Membrane Proteins
  • OCLN protein, human
  • Occludin
  • Ocln protein, mouse