Abstract: The present disclosure provides methods and compositions for conducting an assay to detect a polynucleotide. In particular, ruthenium complexes having reduction potentials that do not coincide with the reduction potential of molecular oxygen are disclosed and amperometric techniques for their use are described. In preferred embodiments, the ruthenium complex is ruthenium (III) pentaamine pyridine and the polynucleotide that is detected is DNA. Further, techniques for enhancing detectable contrast between hybridized and unhybridized nucleic acids are disclosed. In particular, the use of elongated target strands as well as the use of uncharged probe strands are discussed.

Abstract: Methods for conducting an assay to detect nucleic acid hybridization are disclosed. In particular, the fabrication of a carbon electrode suited to nucleic acid hybridization detection is described. In some preferred embodiments, a micro array of carbon electrodes is constructed using photolithography. The final step in the photolithography process involves developing a solder mask with an alkaline solution. The alkaline solution oxidizes the carbon surface producing surface carboxylic acid groups. The surface carboxylic acid groups are reacted with EDC or DCC and NHS to produce NHS esters. Immobilization of NEUTRAVIDIN® onto the electrode surface is effected by reaction with the surface NHS ester groups. A biotinylated probe DNA molecule is then attached to the electrode via binding between the biotin group and the immobilized NEUTRAVIDIN®. The resulting electrode can be used to detect hybridization between the probe DNA and complementary target DNA.

Abstract: The present disclosure provides methods and compositions for conducting an assay to detect a polynucleotide. In particular, ruthenium complexes having reduction potentials that do not coincide with the reduction potential of molecular oxygen are disclosed and amperometric techniques for their use are described. In preferred embodiments, the ruthenium complex is ruthenium (III) pentaamine pyridine and the polynucleotide that is detected is DNA. Further, techniques for enhancing detectable contrast between hybridized and unhybridized nucleic acids are disclosed. In particular, the use of elongated target strands as well as the use of uncharged probe strands are discussed.

Abstract: The present disclosure provides methods and compositions for conducting an assay to detect a polynucleotide. In particular, ruthenium complexes having reduction potentials that do not coincide with the reduction potential of molecular oxygen are disclosed and amperometric techniques for their use are described. In preferred embodiments, the ruthenium complex is ruthenium (III) pentaamine pyridine and the polynucleotide that is detected is DNA. Further, techniques for enhancing detectable contrast between hybridized and unhybridized nucleic acids are disclosed. In particular, the use of elongated target strands as well as the use of uncharged probe strands are discussed.

Abstract: The present disclosure provides methods and compositions for conducting an assay to detect nucleic acid hybridization in the presence of oxygen. In particular, ruthenium complexes having a reduction potential that does not coincide with the reduction potential of molecular oxygen are disclosed and amperometric techniques for their use are described. In preferred embodiments, the ruthenium complex is ruthenium (III) pentaamine pyridine and the nucleic acid hybridization event that is detected is DNA hybridization. Further, techniques for enhancing detectable contrast between hybridized and unhybridized nucleic acids are disclosed. In particular, the use of elongated target strands as well as the use of uncharged probe strands are discussed.

Abstract: The present invention disclosure provides methods and compositions for a universal tag assay wherein a universal detector having detection probes is incubated with tagged molecules having identifier tags corresponding to targets, and hybridization of an identifier tag to a complementary detection probe indicates the presence of the corresponding target in the material being assayed. In particular, the invention disclosure provides methods and compositions for detecting target nucleotide sequences in a sample by target-dependent manipulations that generate tagged molecules having identifier tags corresponding to target nucleotide sequence, where incubation of tagged molecules with a universal detector having detection probes permits hybridization of identifier tags to complementary detection probes, thereby indicating the presence of the target nucleotide sequence corresponding to each identifier tag.

Abstract: The present disclosure provides methods and compositions for conducting an assay to detect nucleic acid hybridization in the presence of oxygen. In particular, ruthenium complexes having a reduction potential that does not coincide with the reduction potential of molecular oxygen are disclosed and amperometric techniques for their use are described. In preferred embodiments, the ruthenium complex is ruthenium (III) pentaamine pyridine and the nucleic acid hybridization event that is detected is DNA hybridization. Further, techniques for enhancing detectable contrast between hybridized and unhybridized nucleic acids are disclosed. In particular, the use of elongated target strands as well as the use of uncharged probe strands are discussed.

Abstract: The present disclosure relates to the detection of somatic cell mutations, particularly as part of a method to screen for cancer or precancer. The disclosure includes techniques for extracting and isolating oligonucleotides from a patient and conducting hybridization assays. Preferred embodiments include a combination of the following steps: extracting a biological sample from a patient, purifying a nucleic acid from a biological sample, amplifying a nucleic acid, isolating a nucleic acid in single stranded form, cyclizing a nucleic acid, elongating a nucleic acid, controlling hybridization stringency, amplifying a nucleic acid on a chip, and detecting hybridization.