title: Endocytosis of liposomes bound to cell surface proteins measured by flow cytofluorometry.
abstract: A new technique for the quantification of cellular receptor-mediated endocytosis has been developed based on the analysis by flow cytometry of ligand-bearing liposomes containing the fluorochrome carboxyfluorescein. Carboxyfluorescein encapsulated at high concentrations in protein A-bearing liposomes is self-quenched. Binding and internalization of such liposomes by cells via antibodies directed towards membrane surface determinants results in the release of the liposome-encapsulated carboxyfluorescein into the cytoplasm causing an increase in cell-associated fluorescence. This increase can be quantified on a flow cytofluorometer.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D004705:Endocytosis; D005353:Fibronectins / Q000276:immunology; D005434:Flow Cytometry / Q000379:methods; D005452:Fluoresceins / Q000378:metabolism; D006183:H-2 Antigens / Q000276:immunology; D008081:Liposomes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008808:Mice, Inbred CBA; D013205:Staphylococcal Protein A / Q000378:metabolism; D013696:Temperature
chemical_list: D000906:Antibodies; D005353:Fibronectins; D005452:Fluoresceins; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D008081:Liposomes; D008565:Membrane Proteins; D013205:Staphylococcal Protein A; C024098:6-carboxyfluorescein