title: Immobilization and stretching of 5'-pyrene-terminated DNA on carbon film deposited on electron microscope grid.
abstract: The immobilization and stretching of randomly coiled DNA molecules on hydrophobic carbon film is a challenging microscopic technique, which possess various applications, especially for genome sequencing. In this report the pyrenyl nucleus is used as an anchor moiety to acquire higher affinity of double stranded DNA to the graphite surface. DNA and pyrene are joined through a linker composed of four aliphatic methylene groups. For the preparation of pyrene-terminated DNA a multifunctional phosphoramidite monomer compound was designed. It contains pyrenylbutoxy group as an anchor moiety for π-stacking attachment to the carbon film, 2-cyanoethyloxy, and diisopropylamino as coupling groups for conjugation to activated oligonucleotide chain or DNA molecule. This monomer derivative was suitable for incorporation into automated solid-phase DNA synthesis and was attached to the 5' terminus of the DNA chain through a phosphodiester linkage. The successful immobilization and stretching of pyrene-terminated DNA was demonstrated by conventional 100 kV transmission electron microscope. The microscopic analysis confirmed the stretched shape of the negatively charged nucleic acid pieces on the hydrophobic carbon film.
authors: Graduate School of Science and Engineering, Saitama University, Shimo-Ohkubo 255, Sakura-Ku, Saitama, 338-8570, Japan.|Laboratory of Engineering NanoBiotechnology, Department of Engineering Geoecology, University of Mining and Geology "St. Ivan Rilski", Sofia, Bulgaria.
authors: Alexandre
authors: A
authors: Loukanov
authors: Department of Infectious Pathology, Hygiene, Technology and Control of Food Stuffs of Animal Origin, Faculty of Veterinary Medicine, University of Forestry, Sofia, Bulgaria.
authors: Chavdar
authors: C
authors: Filipov
authors: Laboratory of Engineering NanoBiotechnology, Department of Engineering Geoecology, University of Mining and Geology "St. Ivan Rilski", Sofia, Bulgaria.
authors: Marta
authors: M
authors: Lecheva
authors: Materials Research Laboratory, University of Nova Gorica, Nova Gorica, SI-5000, Slovenia.
authors: Saim
authors: S
authors: Emin
mesh_terms: D002244:Carbon / Q000378:metabolism*; D004247:DNA / Q000138:chemical synthesis* / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron; D011721:Pyrenes / Q000378:metabolism*
chemical_list: D011721:Pyrenes; D002244:Carbon; D004247:DNA; C030984:pyrene
keywords: 2-cyanoethyl pyrenyl N,N-diisopropylphosphoramidite; 5′-pyrene-terminated DNA; immobilization and stretching of DNA