Open Access Highly Accessed Research article

Quantum dot imaging for embryonic stem cells

Shuan Lin1, Xiaoyan Xie1, Manishkumar R Patel1, Yao-Hung Yang1, Zongjin Li1, Feng Cao1, Oliver Gheysens1, Yan Zhang1, Sanjiv S Gambhir12, Jiang Hong Rao1 and Joseph C Wu13*

Author affiliations

1 Molecular Imaging Program at Stanford (MIPS) and Bio-X Program, Department of Radiology, Stanford University, Stanford, CA 94305, USA

2 Department of Medicine, Division of Cardiology, Stanford University School of Medicine, Stanford, CA 94305, USA

3 Department of Bioengineering, Stanford University, Stanford, CA 94305, USA

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Citation and License

BMC Biotechnology 2007, 7:67  doi:10.1186/1472-6750-7-67

Published: 9 October 2007



Semiconductor quantum dots (QDs) hold increasing potential for cellular imaging both in vitro and in vivo. In this report, we aimed to evaluate in vivo multiplex imaging of mouse embryonic stem (ES) cells labeled with Qtracker delivered quantum dots (QDs).


Murine embryonic stem (ES) cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, and differentiation were not adversely affected by QDs compared with non-labeled control cells (P = NS). Afterward, labeled ES cells were injected subcutaneously onto the backs of athymic nude mice. These labeled ES cells could be imaged with good contrast with one single excitation wavelength. With the same excitation wavelength, the signal intensity, defined as (total signal-background)/exposure time in millisecond was 11 ± 2 for cells labeled with QD 525, 12 ± 9 for QD 565, 176 ± 81 for QD 605, 176 ± 136 for QD 655, 167 ± 104 for QD 705, and 1,713 ± 482 for QD 800. Finally, we have shown that QD 800 offers greater fluorescent intensity than the other QDs tested.


In summary, this is the first demonstration of in vivo multiplex imaging of mouse ES cells labeled QDs. Upon further improvements, QDs will have a greater potential for tracking stem cells within deep tissues. These results provide a promising tool for imaging stem cell therapy non-invasively in vivo.