title: DNA dangling-end-induced colloidal stabilization of gold nanoparticles for colorimetric single-nucleotide polymorphism genotyping.
abstract: A single-nucleotide polymorphism (SNP) detection method was developed by combining single-base primer extension and salt-induced aggregation of gold nanoparticles densely functionalized with double-stranded DNA (dsDNA-AuNP). The dsDNA-AuNPs undergo rapid aggregation in a medium of high ionic strength, whereas particles having a single-base protrusion at the outermost surface disperse stably, allowing detection of a single-base difference in length by color changes. When SNP typing primers are used as analytes to hybridize to the single-stranded DNA on the AuNP surface, the resulting dsDNA-AuNP works as a visual indicator of single-base extension. A set of four extension reaction mixtures is prepared using each of ddNTPs and subsequently subjected to the aggregation assay. Three mixtures involving ddNTP that is not complementary to the SNP site in the target produce the aggregates that exhibit a purple color. In contrast, one mixture with the complementary ddNTP generates the single-base protrusion and appears red. This method could potentially be used in clinical diagnostics for personalized medicine.
authors.affiliation: Bioengineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan), Fax: (+81) 4-8462-4658.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Hiroto
authors.initials: H
authors.lastname: Shikagawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Kanayama
authors.forename: Tohru
authors.initials: T
authors.lastname: Takarada
authors.forename: Mizuo
authors.initials: M
authors.lastname: Maeda
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques; D003124:Colorimetry / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D019937:Diagnostic Techniques and Procedures; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D020641:Polymorphism, Single Nucleotide
chemical_list: D004277:DNA, Single-Stranded; D006046:Gold; D004247:DNA
keywords: DNA; gold; nanoparticles; primer extension; single-nucleotide polymorphism