Labeling and tracking of human mesenchymal stem cells using near-infrared technology.

The recently developed near-infrared (NIR) light imaging technology combines low background noise with deep tissue penetration and readily allows imaging and tracking of NIR-labeled cells, following transplantation in small animal model of diseases. The real-time and longitudinal detection of grafted cells in vivo, as well as their rapid ex vivo localization, may further clarify graft interactions with the surrounding, in target and nontarget organs throughout the body, over time. The present chapter describes a protocol for (1) the efficient labeling of human mesenchymal stem cells (hMSCs) using a membrane intercalating dye, emitting in the NIR 815 nm spectrum; (2) the stereotaxic transplantation of NIR 815-hMSCs in rodent model of Parkinson's disease; and (3) the longitudinal in vivo detection of the grafted cells and the subsequent ex vivo imaging in selected tissues.