To study the PFC distribution over the different compartments of the blood, at various points in time after injection of the PFC emulsion blood samples were taken, subjected to density gradient centrifugation, and analyzed by 1H/19F MRI.

The figure above clearly shows the predominant localization of the 19F signal witin the layer of the mononuclear cells. Additional experiments with rhodamine-labelled PFCs and subsequent analysis of the blood by flow cytometry confirmed the preferential uptake of the PFC nanoparticles by monocytes/macrophages. For a detailed description and discussion of the respective experiments please have a look at: Flögel et al, 2008.