Glowing DNA allows for high speed disease detection

October 11, 2012

The influence of the nucleic acid secondary structure on fast (1 hour) formation of bright red emissive silver nanoclusters in a DNA sequence, designed for the detection of a microRNA sequence (credit: Pratik Shah et al./ACS Nano)

University of Copenhagen scientists have invented a method that promises to shave days off the lab work done to reveal diseases, using cheap methods and easy to use analytical apparatuses.

Many diseases, including cancers, leave genetic clues in the body just as criminals leave DNA at the scene of a crime. But tools to detect the DNA-like sickness clues known as miRNAs, tend to be slow and expensive.

Chemistry researcher Tom Vosch and plant molecular biologist Seong Wook Yang invented a DNA sensor, coupling genetic material to a luminous molecule that goes dark only in the presence of a specific target.

DNA-clues help detecting disease

Individuals with disease are likely to have a unique miRNA profile. And because the profiles of miRNAs vary by type of cancer, finding it proves beyond a reasonable doubt what made the patient sick.

The new detection method exploits a natural quality of genetic material. A single DNA strand is made up of molecules (bases), ordered in a unique combination. When two strands join to form their famous double helix, they do so by sticking to complementary copies of themselves. Likewise strands tailored to match particular miRNAs will stick to the real thing with uncanny precision.

Tom Vosch is specialized in studying molecules that light up. Seong Wook Yang is specialized in miRNA. Together they figured out how to attach the light-emitting molecules to DNA sensors for miRNA detection.

Likely to lead to high speed cancer diagnostics

Vosch and Yang tested their Silver Nano Cluster DNA probes with eight different types of genetic material and found that they work outright with six of them. But more importantly, they figured out how to fix the ones, that didn’t.

This indicates that their method will work in the detection of almost all types of miRNAs, also in all likelihood for cancer related miRNAs. The most widespread current miRNA detection method requires some 48 hours of lab work from raw samples. The new method can do the same job of detection within a maximum of 6 hours.