Methods for Manipulating DNA Molecules in a Micrometer Scale using Optical Techniques

1. Methods for Manipulating DNA Molecules in a Micrometer Scale using Optical Techniques July 13, 2004 Summarized by Ji-Yoon Park

2. Abstract • Optical method • Control the position & reaction of DNA molecules in a micrometer scale • Two single laser beams for optical manipulation & temperature control • Independent control

3. Introduction • Optical computing • Using inherent property of light • Fast propagation, parallelism, and a large bandwidth • Example: • Vertical cavity surface-emitting lasers (VCSELs) • Diffractive optical elements (DOEs) • DNA & Light: high-performance information system • In this paper • Methods for controlling the position & reaction of DNA in micrometer scale

4. Optically Assisted DNA Computing Figure 1. The basic concept of optically assisted DNA computing

5. Manipulation of DNA • Optical manipulation • A method for non-invasively manipulating an object with a radiation pressure force induced between light and the object • DNA cluster • DNA strands connected to a microscopic bead

6. Manipulation of DNA using Optical Techniques Figure 2. A method for controlling the temperature of a solution in a micrometer scale

7. Experimental Section (1/2) • Three step operation • Attaching the DNA cluster to the bead • Translation of the bead • Detaching the DNA cluster from the bead

8. Experimental Section (2/2) • Anti-tag sequence immobilization to bead (diameter: 6 µm)5’-biotin-CATAG TACAA ATCTT ACCTC ATTTC AGTTA CTGAT CCACG-3’ • Alexa Fluor 647 attach the tag sequence 5’-Alexa 647- CGTGG ATCAG TAACT GAAAT GAGGT AAGAT TTGTACTATG-3’ • Hybridization with anti-tag sequence and tag sequence • Extraction of DNA cluster • Substrate coating with titanylphthalocyanine (0.15 µm) & gold deposition • Thiol-modified anti-tag sequence binding to substrate

9. Experimental Setup Figure 3. Experimental setup

10. Figure 4. Experimental result of detachment of information DNA from a substrate

11. Dependence of the Fluorescence Intensity Figure 5. Dependence of the fluorescent intensity on irradiation cycle when the laser beam for temperature control is used. (i) fluorescent molecules are attached to tag DNA (ii) Bead on the anti-tag DNA with fluorescent molecules Irradiation cycle: 5 mW for 15 sec & stop for 4 sec

12. Fluorescence Images Figure 6. Experimental result of translation and detachment of DNA. (a) at initial state (b) after translation (c) after detachment: 3 mW for 1 min

13. Fluorescence Intensity of Microwell Array • anti-tag DNA attachment • Tag DNA binding • Irradiation (4 mW for 1 min) • Fluorescence intensity Figure 7. Fluorescent intensity of a DNA cluster (a) before and (b) after irradiating with a laser beam

14. Conclusions • Develop methods for manipulating DNA molecules in a micrometer scale with optical techniques • The position and reaction of DNA are controlled independently using two laser beams with different wavelengths