title: Determination of microsatellite repeats in the human thyroid peroxidase (TPOX) gene using an automated gene analysis system with nanoscale engineered biomagnetite.
abstract: The number of repeat in the microsatellite region (AATG)(5-14) of the human thyroid peroxidase gene (TOPX) was determined using an automated DNA analysis system with nano-scale engineered biomagnetite. Thermal melting curve analysis of DNA duplexes on biomagnetite indicated that shorter repeat sequences (less than 9 repeats) were easily discriminated. However, it was difficult to determine the number of repeats at more than nine. In order to improve the selectivity of this method for the longer repeats, a "double probe hybridization assay" was performed in which an intermediate probe was used to replace a target repeat sequence having more than 9 repeats with a shorter sequence possessing less than 9 repeats. Thermal probe melting curve analyses and Tm determination confirmed that the target with 10 repeats was converted to 5 repeats, 11 repeats converted to 4 and 12 to 3, respectively. Furthermore, rapid determination of repeat numbers was possible by measuring fluorescence intensities obtained by probe dissociation at 56 and 66 degrees C, and 40, 60 and 80 degrees C for signal normalization.
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Koganei, Tokyo 184-8588, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Kohei
authors.initials: K
authors.lastname: Maruyama
authors.forename: Haruko
authors.initials: H
authors.lastname: Takeyama
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsunaga
mesh_terms: D052203:Ferrosoferric Oxide; D006801:Humans; D007453:Iodide Peroxidase / Q000235:genetics*; D018895:Microsatellite Repeats; D036103:Nanotechnology; D017422:Sequence Analysis, DNA
chemical_list: D007453:Iodide Peroxidase; D052203:Ferrosoferric Oxide