title: A novel flow-cytometry-based assay for cellular uptake studies of polyelectrolyte microcapsules.
abstract: 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.
authors.affiliation: Institut für Experimentelle Physik I and Paul Flechsig Institut, Universität Leipzig, Leipzig, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Semmling
authors.forename: Oliver
authors.initials: O
authors.lastname: Kreft
authors.forename: Almudena
authors.initials: A
authors.lastname: Muñoz Javier
authors.forename: Gleb B
authors.initials: GB
authors.lastname: Sukhorukov
authors.forename: Josef
authors.initials: J
authors.lastname: Käs
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Parak
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002214:Capsules / Q000378:metabolism*; D002460:Cell Line; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D051379:Mice; D011108:Polymers / Q000378:metabolism*
chemical_list: D002214:Capsules; D011108:Polymers