Labeling of hematopoietic stem cells by Tat peptide conjugated quantum dots for cell tracking in mouse body.

Fluorescent quantum dots have great potential to act as labeling tools in biological research, especially cellular tracking and imaging. Tat peptide conjugated quantum dots were introduced into living human hematopoietic stem cells (HSCs). The internalized quantum dots were assessed by laser confocal microscope and flow cytometer. The quantum dots labeled HSCs were injected intravenously into the tail veins of NOD/SCID beta2M null mice. The tissue collections in the major organs were examined with fluorescence microscope to assess the distribution of transplanted stem cells. HSCs with internalized quantum dots offer a promising approach for stem cell transplantation, which will hold a significant impact on stem cell based therapy for several disorders, especially to cure leukemia in current China.