title: Quantitative and discriminative analysis of nucleic acid samples using luminometric nonspecific nanoparticle methods.
abstract: Homogeneous simple assays utilizing luminescence quenching and time-resolved luminescence resonance energy transfer (TR-LRET) were developed for the quantification of nucleic acids without sequence information. Nucleic acids prevent the adsorption of a protein to europium nanoparticles which is detected as a luminescence quenching of europium nanoparticles with a soluble quencher or as a decrease of TR-LRET from europium nanoparticles to the acceptor dye. Contrary to the existing methods based on fluorescent dye binding to nucleic acids, equal sensitivities for both single- (ssDNA) and double-stranded DNA (dsDNA) were measured and a detection limit of 60 pg was calculated for the quenching assay. The average coefficient of variation was 5% for the quenching assay and 8% for the TR-LRET assay. The TR-LRET assay was also combined with a nucleic acid dye selective to dsDNA in a single tube assay to measure the total concentration of DNA and the ratio of ssDNA and dsDNA in the mixture. To our knowledge, such a multiplexed assay is not accomplished with commercially available assays.
authors.affiliation: Laboratory of Materials Chemistry and Chemical Analysis, Department of Chemistry, University of Turku, Vatselankatu 2, 20500 Turku, Finland. sari.pihlasalo@utu.fi.
authors.forename: S
authors.initials: S
authors.lastname: Pihlasalo
authors.forename: L
authors.initials: L
authors.lastname: Mariani
authors.forename: H
authors.initials: H
authors.lastname: Härmä