Photonic translation of DNAs between microscopic beads and a substrate for a photonic DNA memory

A DNA memory is a storage system utilizing inherent features of DNA, which is promising as a fundamental technology of nanoscale computing. Realizing a practical DNA memory requires establishment of a method for accessing to and controlling certain DNA strands among a lot of strands in a solution with high accuracy and selectivity. For addressing this issue, we have proposed a DNA memory using photonic techniques: the photonic DNA memory. Manipulation of information by using DNAs on a nanoscale and light on a microscale is effective in achieving a high capacity and flexible memory. This paper reports on experimental results of photonic translation of DNAs containing data between microscopic beads and a substrate. The technique is expected to be useful in writing, transferring, and reading necessary information in a photonic DNA memory effectively. In the experiments, we prepared a glass substrate coated with titanylphthalocyanine for light absorption and gold for DNA attachment. Data container DNA strands, which were labeled by fluorescence-dye for observation, were attached on the substrate by hybridization with their complementary strands immobilized on the substrate; then a solution containing 6-micrometer-diameter beads on which DNA strands including the complementary sequence of the data container DNA was placed on the substrate. After a bead was irradiated with a laser beam and translated on the substrate, the fluorescence intensity of the substrate decreased and that of the bead increased. The result indicates that the data container DNA was moved from the substrate to the bead owing to change of the temperature of the solution at the irradiated area.