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Thursday, March 19, 2009

Physical manipulation of single-molecule DNA using microbead and its application to analysis of DNA–protein interaction

Hirofumi Kurita, Hachiro Yasuda, Kazunori Takashima, Shinji Katsura and Akira Mizuno

We carried out an individual DNA manipulation using an optical trapping for a microbead. This manipulation system is based on a fluorescent microscopy equipped with an IR laser. Both ends of linear DNA molecule were labeled with a biotin and a thiol group, respectively. Then the biotinylated end was attached to a microbead, and the other was immobilized on a thiol-linkable glass surface. We controlled the form of an individual DNA molecule by moving the focal point of IR laser, which trapped the microbead. In addition, we applied single-molecule approach to analyze DNA hydrolysis. We also used microchannel for single-molecule observation of DNA hydrolysis. The shortening of DNA in length caused by enzymatic hydrolysis was observed in real-time. The single-molecule DNA manipulation should contribute to elucidate detailed mechanisms of DNA–protein interactions.

DOI

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