title: Base pair mismatch recognition using plasmon resonant particle labels.
abstract: We demonstrate the use of silver plasmon resonant particles (PRPs), as reporter labels, in a microarray-based DNA hybridization assay in which we screen for a known polymorphic site in the breast cancer gene BRCA1. PRPs (40-100 nm in diameter) image as diffraction-limited points of colored light in a standard microscope equipped with dark-field illumination, and can be individually identified and discriminated against background scatter. Rather than overall intensity, the number of PRPs counted in a CCD image by a software algorithm serves as the signal in these assays. In a typical PRP hybridization assay, we achieve a detection sensitivity that is approximately 60 x greater than that achieved by using fluorescent labels. We conclude that single particle counting is robust, generally applicable to a wide variety of assay platforms, and can be integrated into low-cost and quantitative detection systems for single nucleotide polymorphism analysis.
authors.affiliation: Seashell Technology, LLC 3252 Holiday Court Suite 227, La Jolla, CA 92037, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Oldenburg
authors.forename: Christine C
authors.initials: CC
authors.lastname: Genick
authors.forename: Keith A
authors.initials: KA
authors.lastname: Clark
authors.forename: David A
authors.initials: DA
authors.lastname: Schultz
mesh_terms: D020137:Base Pair Mismatch; D001483:Base Sequence; D019921:Biotinylation; D001943:Breast Neoplasms / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics*; D005260:Female; D019398:Genes, BRCA1; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*; D013698:Templates, Genetic
chemical_list: D004247:DNA