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AKB: Biologische Physik

AKB 200: Poster Session II

AKB 200.46: Poster

Dienstag, 8. März 2005, 17:00–19:00, Poster TU C

Biochemical synthesis of periodic DNA nanotemplates — •Stefan Beyer und Friedrich C. Simmel — Department Physik, LMU München, Geschwister-Scholl-Platz 1, 80539 München

Rolling circle amplification (RCA), a biochemical method established in genetics and biosensing, can be used to produce DNA building blocks for the self-assembly of nanostructures. In RCA, small circular single-stranded oligonucleotides serve as templates for the polymerization of the complementary strand. The polymerase (phi29 DNA polymerase) used for this process has a unique strand displacement activity. This allows it to continue with the polymerization process after the completion of one cycle without unbinding from the substrate. After one polymerization cycle the leading strand is removed and another cycle begins. The result of many of such cycles is a long single DNA strand with a repetitive sequence. Such a strand can be functionalized by hybridization with biotinylated DNA strands complementary to the repetition unit. The resulting DNA nanotemplate can be used to align biotin-binding nanoparticles (streptavidin or anti-biotin conjugates) into one-dimensional arrays. The constructs are analyzed by atomic force microscopy, scanning electron microscopy, gel electrophoresis and fluorescence microscopy. RCA proves to be a very simple, efficient and inexpensive way to create long periodic DNA sequences which can serve as templates for linear structures composed of nanoobjects.