Single-Molecule Strategies for DNA and RNA Diagnostics

Since the discovery of the DNA structure more than 60 years ago, the use of fluorescence tools for molecular diagnostics of nucleic acids has experienced an astonishing growth. In particular, during the last decade, the development of specific techniques to detect and analyse the structure and dynamics of nucleic acids at single-molecule level has revolutionised the field, and now it is possible to sequence a complete genome in record-breaking time and to get insights into structure and function of nucleic acids with an unprecedented level of detail. In this chapter, we start by reviewing the basic concepts regarding state-of-the-art single-molecule diagnostics of nucleic acids, and we describe in detail the most recent advances on the field, ranging from DNA sequencing and nucleic acid-based sensing to the analysis of functional RNAs involved in gene regulation and catalysis. The final sections are devoted to explore the latest RNA aptamers for imaging live cells and the next generation of hybrid technologies based on real-time manipulation of their structure and dynamics one at a time.