New Discovery Reveals DNA Naturally Fluoresces

A team of researchers at Northwestern University’s Engineering school came across an unprecedented phenomenon: “blinking” or fluorescing DNA. 

School textbooks emphasize that macromolecules like DNA and RNA do not naturally fluoresce, and therefore require special fluorescent dyes to be viewed and imaged. This new breakthrough may potentially enable researchers to forgo these often toxic dyes and harness the newly discovered natural fluorescent processes to image DNA.  

The toxicity of dyes currently in use in the lab can make imaging of living cells less precise as cells tend to die soon after application.  Certain dyes do allow researchers to image living cells for longer periods of time, but do so by causing the cell to die slower. Using the current method, it is unclear whether researchers are learning more about the actual processes that occur in living cells, or simply those specific to dying ones. The research conducted by professors Vadim Backman, Hao Zhang, and Cheng Sun at Northwestern University has the potential to cause a paradigm shift in our view of DNA and these dyes.

Normally, the team discovered, DNA molecules are in a sort of “dark state,” in which they do not absorb or emit light. This state can be compared to a “resting” state of a high performance sprinter who alternates between not doing much exercise to an intensive, brief, running period. DNA likewise only fluoresces for a short period of time and returns to the “dark state.” 

When the DNA is illuminated with visible light, the molecules become excited and will light up so that they can be imaged without fluorescent stains. With the right wavelength, they can even be lit up better than they would with the best, most powerful fluorescent labels.

This new research development could lead to a label-free, higher resolution method for imaging DNA and for understanding life processes in the cell at large.

For more information, please visit: www.northwestern.edu

 

 

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