Article

Labeling Stem Cells with Fluorescent Dyes for non-invasive Detection with Optical Imaging

Contrast Agent Research Group at the Center for Molecular and Functional Imaging, Department of Radiology, University of California San Francisco, USA.
Journal of Visualized Experiments (Impact Factor: 1.33). 02/2008; 14(14). DOI: 10.3791/686
Source: PubMed

ABSTRACT Optical imaging (OI) is an easy, fast and inexpensive tool for in vivo monitoring of new stem cell based therapies. The technique is based on ex vivo labeling of stem cells with a fluorescent dye, subsequent intravenous injection of the labeled cells and visualization of their accumulation in specific target organs or pathologies. The presented technique demonstrates how we label human mesenchymal stem cells (hMSC) by simple incubation with the lipophilic fluorescent dye DiD (C67H103CIN2O3S) and how we label human embryonic stem cells (hESC) with the FDA approved fluorescent dye Indocyanine Green (ICG). The uptake mechanism is via adherence and diffusion of the lypophilic dye across the phospholipid cell membrane bilayer. The labeling efficiency is usually improved if the cells are incubated with the dye in serum-free media as opposed to incubation in serum-containing media. Furthermore, the addition of the transfection agent Protamine Sulfate significantly improves contrast agent uptake.

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