Live cell imaging of DNA and RNA with fluorescent signal amplification and background reduction techniques

Abstract

Illuminating DNA and RNA dynamics in live cell can elucidate their life cycle and related biochemical activities. Various protocols have been developed for labeling the regions of interest in DNA and RNA molecules with different types of fluorescent probes. For example, CRISPR-based techniques have been extensively used for imaging genomic loci. However, some DNA and RNA molecules can still be difficult to tag and observe dynamically, such as genomic loci in non-repetitive regions. In this review, we will discuss the toolbox of techniques and methodologies that have been developed for imaging DNA and RNA. We will also introduce optimized systems that provide enhanced signal intensity or low background fluorescence for those difficult-to-tag molecules. These strategies can provide new insights for researchers when designing and using techniques to visualize DNA or RNA molecules.

Keywords: DNA and RNA dynamics; fluorescent background reduction; live cell imaging; microscopy; signal amplification.

FIGURE 1

Dynamic DNA and RNA imaging tools. Images showing DNA (double strand) and RNA (single strand) tagging tools with different principles. Green spots represent fluorescent protein or fluorophore.

FIGURE 2

Schematics of signal amplification and background reduction. Upper image shows the fluorescent signal amplification strategy for labeling target loci. Lower image shows the fluorescent background reduction strategy for labeling target loci.