Table of Contents
International Journal of Molecular Imaging
Volume 2012, Article ID 501579, 10 pages
Review Article

Engineering Molecular Beacons for Intracellular Imaging

1Center for Research at Bio/Nano Interface and Department of Chemistry and Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, FL 32611-7200, USA
2State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemical Biology, Key Laboratory of Analytical Science, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China

Received 7 August 2012; Accepted 21 September 2012

Academic Editor: Xiaoyuan Chen

Copyright © 2012 Cuichen Sam Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Molecular beacons (MBs) represent a class of nucleic acid probes with unique DNA hairpin structures that specifically target complementary DNA or RNA. The inherent “OFF” to “ON” signal transduction mechanism of MBs makes them promising molecular probes for real-time imaging of DNA/RNA in living cells. However, conventional MBs have been challenged with such issues as false-positive signals and poor biostability in complex cellular matrices. This paper describes the novel engineering steps used to improve the fluorescence signal and reduce to background fluorescence, as well as the incorporation of unnatural nucleotide bases to increase the resistance of MBs to nuclease degradation for application in such fields as chemical analysis, biotechnology, and clinical medicine. The applications of these de novo MBs for single-cell imaging will be also discussed.