A few weeks ago I stumbled upon an MIT Technology Review article about a DNA-based dark matter detector. As a biologist I thought the idea was strange, since I didn't see how DNA would interact with dark matter in a way that a more easily manufacturable material such as silicon wouldn't. I put off reading the article until today and now that I have, I still don't get the fundamental premise. First, a link to the article: http://www.technologyreview.com/view/428391/revolutionary-dna-tracking-chamber-could-detect/ The idea seems to be that you have an array of single stranded DNA attached to a gold chip. A "dark matter particle" transfers kinetic energy into a gold nucleus, sending it flying through the DNA array and severing the chemical bonds along its trajectory. The severed DNA is collected, amplified via PCR (a molecular biology technique for rapid DNA replication, for those who haven't heard of it), and sequenced. Since each DNA strand in the array has a different sequence, the identity of the severed DNA strands provides a record of the 3-dimensional direction in which the gold nucleus traveled. This is then compared to the time of day to test the hypothesis that the earth travels into the dark matter field while rotating towards Cygnus, and away from it while rotating away from Cygnus. Since I have no knowledge at all about dark matter, I have a couple questions about the proposed detector. 1: Is there any evidence that dark matter interacts with gold? Why particularly gold instead of another element? 2: If there is such evidence, why rely on a prototype, expensive, never-before-tested DNA-based detector rather than a detector film such as that used for Rutherford backscattering analysis or other surface science techniques? 3: If the detector is built and produces a signal, would it be reasonable to assume that the signal comes from dark matter rather than any other process such as residual radioactivity that could knock out a nucleus? Thanks!