2231 results about "DNA polymerase" patented technology

Methods and a kit are provided for selectively and exponentially amplifying nucleic acids and include the use of a helicase preparation and a DNA polymerase such that the amplification can be performed isothermally.

Since conventional DNA sequence analyzing technologies are based on the fundamental principle of fluorescent detection, expensive, complex optical systems and laser sources have been necessary.A field-effect device for gene detection of the present invention analyzes a base sequence by immobilizing a single-strand nucleic acid probe at a gate portion, inducing hybridization at the gate portion to form a double-stranded DNA, inducing elongation reaction by adding a DNA polymerase and one of the substrates, and measuring the electrical characteristic of the field-effect device caused by elongation reaction.Since the elongation reaction of one base induced at the gate portion can be directly converted to an electrical signal, expensive lasers or complex optical systems are not needed. Thus, a small gene polymorphism detection system that can conduct measurement at high precision can be provided.

Methods and a kit are provided for selectively and exponentially amplifying nucleic acids and include the use of a single strand helicase preparation or a thermostable helicase in the absence of a single strand binding protein and a DNA polymerase such that the amplification can be performed isothermally.

A method is described for the direct, exponential amplification and sequencing ("DEXAS") of a DNA molecule from a complex mixture of nucleic acids, wherein truncated DNA molecules as well as DNA molecules of full length are synthesized simultaneously and exponentially between two positions on the said DNA molecule, which initially contains a DNA molecule in a thermocycling reaction, a first primer, a second primer, a reaction buffer, a thermostable DNA polymerase, a thermostable pyrophosphatase (optionally), deoxynucleotides or derivatives thereof and a dideoxynucleotide or derivatives thereof. In a preferred embodiment of the method of the invention, direct sequencing of RNA can be performed using one polymerase having a Tabor-Richardson mutation, or a functional derivative thereof, and reverse transcriptase activity. In a more preferred embodiment of the method of the invention, direct sequencing of RNA can be performed in one step, in one vessel.

The present invention relates to a novel method for analyzing nucleic acid sequences based on real-time detection of DNA polymerase-catalyzed incorporation of each of the four nucleotide bases, supplied individually and serially in a microfluidic system, to a reaction cell containing a template system comprising a DNA fragment of unknown sequence and an oligonucleotide primer. Incorporation of a nucleotide base into the template system can be detected by any of a variety of methods including but not limited to fluorescence and chemiluminescence detection. Alternatively, microcalorimetic detection of the heat generated by the incorporation of a nucleotide into the extending template system using thermopile, thermistor and refractive index measurements can be used to detect extension reactions.

This disclosure describes related novel methods for Recombinase-Polymerase Amplification (RPA) of a target DNA that exploit the properties of recombinase and related proteins, to invade double-stranded DNA with single stranded homologous DNA permitting sequence specific priming of DNA polymerase reactions. The disclosed methods have the advantage of not requiring thermocycling or thermophilic enzymes, thus offering easy and affordable implementation and portability relative to other amplification methods. Further RPA reactions using light and otherwise, methods to determine the nature of amplified species without a need for gel electrophoresis, methods to improve and optimize signal to noise ratios in RPA reactions, methods to optimize oligonucleotide primer function, methods to control carry-over contamination, and methods to employ sequence-specific third ‘specificity’ probes. Further described are novel properties and approaches for use of probes monitored by light in dynamic recombination environments.

A thermal cycling method and device is disclosed. The device comprises a sample chamber whose temperature can be rapidly and accurately modulated over a range of temperatures needed to carry out a number of biological procedures, such a the DNA polymerase chain reaction. Biological samples are placed in glass micro capillary tubes and then located inside the sample chamber. A programmable controller regulates the temperature of the sample inside the sample chamber. Once a heating cycle is completed, the controller opens a door to the chamber for venting hot air out and cool ambient air is moved in. Temperature versus time profiles corresponding to optimum denaturation, annealing and elongation temperatures for amplification of DNA are achieved by the present invention.