Intracellular endosomal magnetic labeling of cells

Cellular imaging encompasses the noninvasive and repetitive imaging of targeted cells and cellular processes in living organisms. Magnetic resonance imaging (MRI), with its excellent spatial resolution, is ideally suited to provide unique information on the location and migration of cells after transplantation or transfusion. This approach requires magnetic prelabeling of the cells of choice. In this chapter, several methods and techniques will be described that can be applied for an efficient intracellular magnetic labeling of cells. In addition, a few basic protocols for the analysis and evaluation of cell labeling will be provided. The chapter will focus on the use of superparamagnetic iron oxides, because they are biocompatible and have strong effects on T2* relaxation. With the currently available magnetic labeling methods, it is anticipated that cellular MRI will find broad applications in biology and medicine.