  Weakly Interacting Massive Particles (WIMPs) may constitute most of the
matter in the Universe. The ability to detect the directionality of recoil
nuclei will considerably facilitate detection of WIMPs. In this paper we
propose a novel type of dark matter detector: detectors made of DNA or RNA
could provide nanometer resolution for tracking, an energy threshold of 0.5
keV, and can operate at room temperature. When a WIMP from the Galactic Halo
elastically scatters off of a nucleus in the detector, the recoiling nucleus
then traverses hundreds of strings of single stranded nucleic acids (ssNA) with
known base sequences and severs ssNA strands along its trajectory. The location
of the break can be identified by amplifying and identifying the segments of
cut ssNA using techniques well known to biologists. Thus the path of the
recoiling nucleus can be tracked to nanometer accuracy. In one such detector
concept, the transducers are nanometer-thick Au-foils of 1m x 1m, and the
direction of recoiling nuclei is measured by "NA Tracking Chamber" consisting
of ordered array of ssNA strands. Polymerase Chain Reaction (PCR) and ssNA
sequencing are used to read-out the detector. The proposed detector is smaller
and cheaper than other alternatives: 1 kg of gold and 0.1 to 4 kg of ssNA
(depending on length and strand density), packed into 0.01m$^3$, can be used to
study 10 GeV WIMPs. A variety of other detector target elements could be used
in this detector to optimize for different WIMP masses and to identify WIMP
properties. By leveraging advances in molecular biology, we aim to achieve
about 1,000-fold better spatial resolution than in conventional WIMP detectors
at reasonable cost.
