APPLICATIONS OF TECHNOLOGY:

• Single-particle tracking
• Targeted delivery and targeted imaging  
• Time- and spatially-resolved cellular imaging to enable a better understanding of kinetic processes, i.e., protein biosynthesis and trafficking, protein-protein interactions, enzyme activity, and RNA transport
• Super-resolution microscopy

ADVANTAGES:

• Allow control of spatial and temporal resolution in bioimaging
• Possess the brightness and stability of quantum dots
• Brighter than proteins and organic molecules currently used in cellular imaging (e.g., GFPs, fluoresceins, rhodamines)
• Rates of uncaging can be varied to enable multicolor photoactivation and imaging
• Like standard quantum dots, can be used in live cells, fixed cells, or in vitro
• Luminescence can be turned on locally, permitting control over which areas of the cells are imaged
• Simple, low-cost activation and real-time imaging

ABSTRACT:

Bruce Cohen from Berkeley Lab has invented new photoactivatable, or "caged," quantum dots. These new probes are non-luminescent under typical microscopic illumination until activated with stronger pulses of UV light.   This is the first time quantum dots have been dequenched using light.

Current bioimaging technologies include photoactivatable organic flourophores and fluorescent proteins; however, the increased brightness and photostability offered by the Berkeley Lab nanocrystals is what sets them apart from conventional imaging agents. Using the Berkeley Lab caged nanocrystals, biological processes can be imaged in live cells while maximizing brightness and minimizing photobleaching. The photostability of these nanocrystals allows individual molecules to be tracked over extended periods.

The Berkeley Lab caged quantum dots permit specific subcellular areas to be luminescent at a given time. For instance, illuminating the contents of the mitochondria would enable all molecules leaving the mitochondria to be tracked in real-time, offering enhanced data on fundamental biological processes and disease states.   

STATUS:

• Available for licensing or collaborative research.

To learn more about licensing a technology from LBNL see http://www.lbl.gov/Tech-Transfer/licensing/index.html.

FOR MORE INFORMATION:

Ajo-Franklin, C., Cohen, B. E., Han, G., Mokari, T., "Caged Quantum Dots," ASAP J. Am. Chem. Soc., 5 Nov 2008.

REFERENCE NUMBER: IB-2521

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• Functionalized Semiconductor Nanocrystals for Imaging Organelles in Live Cells, IB-2045
• New Multimodal Probes Compatible with Fluorescence and MRI, JIB-2075
• Quantum Dot Based Cell Motility, Invasion, and Metastasis Assays, IB-1755