Fluorescent probes for intracellular RNA tracking

The Need: Intracellular RNA fluorescence labeling is a crucial technique for studying cellular processes and understanding gene expression. However, the conventional MS2 labeling method using protein fusion labels can have drawbacks, such as increased mass, potential steric accessibility issues, and interference with native RNA biology. There is a need for an alternative method that can efficiently and minimally perturbatively label RNA of interest without the use of cumbersome protein fusion labels.

The Technology: Our technology, FLURIL tagging, introduces a novel approach to intracellular RNA and DNA tracking. It utilizes genetically encoded, uridine-rich internal loops (URILs) in RNA, consisting of four contiguous UU pairs, which can be specifically targeted with 1 kD bifacial peptide nucleic acids (bPNAs). This triplex hybridization approach allows for precise and effective labeling of RNA without significant structural perturbation.

Commercial Applications:

  • Cellular Biology Research: FLURIL tagging enables researchers to label and track RNA and RNA-protein complexes (RNPs) in fixed and live cells with high specificity and minimal disturbance to native cellular processes.
  • Gene Expression Studies: FLURIL tagging provides a valuable tool for studying gene expression patterns and dynamics within cells, aiding in various genetic research applications.
  • Drug Development: The technology can be applied in drug discovery to study the effects of candidate drugs on gene expression and RNA regulation, potentially leading to the identification of novel therapeutic targets.


  • Light Molecular Footprint: FLURIL tagging avoids the use of bulky protein fusion labels, resulting in minimal added mass to the bound RNA and reduced steric hindrance, preserving native RNA biology and ensuring accurate results.
  • Enhanced Imaging Signal: FLURIL-tagged RNA exhibits a significantly higher signal-to-background ratio compared to traditional MS2 labeling, providing clearer and more reliable data for researchers.
  • Compatibility with Existing Methods: Researchers can seamlessly integrate FLURIL tagging into their current RNA labeling workflows, allowing for a smooth transition to this improved and versatile technique.

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