A novel flow-cytometry-based assay for cellular uptake studies of polyelectrolyte microcapsules

Maximilian Semmling, Oliver Kreft, Almudena Muñoz Javier, Gleb B. Sukhorukov, Josef Käs, Wolfgang J. Parak

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)


A flow-cytometry-based assay is presented with which the uptake of polyelectrolyte capsules can be quantified. The cavity of the capsules is loaded with the pH-sensitive dye SNARF, which emits in the red and green in alkaline and acidic environments, respectively. By recording the fluorescence intensities in the red and green channels, the localization of capsules associated with cells can be determined. Capsules adherent to the outer cell membrane fluoresce in the red due to the alkaline pH of the cell medium, whereas capsules internalized by cells fluoresce in the green due to the acidic pH in the endosomal/lysosomal/phagosomal compartments in which incorporated capsules are located. Adding the SNARF readout to the scattering signal typically derived with flow cytometry analysis allows for a more detailed quantitative analysis of particle uptake, which can also distinguish between adherent and ingested particles.

Original languageEnglish
Pages (from-to)1763-1768
Number of pages6
Issue number10
Publication statusPublished - Oct 2008
Externally publishedYes


  • Cell adhesion
  • Flow cytometry
  • Fluorescence
  • Microcapsules
  • Polyelectrolytes


Dive into the research topics of 'A novel flow-cytometry-based assay for cellular uptake studies of polyelectrolyte microcapsules'. Together they form a unique fingerprint.

Cite this