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