摘要:
Amplification and sequencing of a selected region of a target nucleic acid polymer are be performed in a single vessel. The sample is added to an amplification mixture containing a thermally stable polymerase and nucleoside feedstocks. Chain terminating dideoxynucleosides are added either at the beginning of the amplification reaction or during the course of the amplification. A thermally stable polymerase which incorporates dideoxynucleotides into an extending oligonucleotide at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleosides can be used in the amplification mixture or added with the chain terminating nucleoside.
摘要:
Evaluation of a sample for the presence and qualitative nature of a microorganism can be performed in a single vessel by combining a natural abundance DNA sample with a sequencing mixture containing a primer pair, a thermally stable polymerase such as ThermoSequenase.TM. which incorporates dideoxynucleotides into an extending nucleic acid polymer at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleotides, nucleotide triphosphate feedstocks, and a chain terminating nucleotide triphosphate. The mixture is processed through multiple thermal cycles for annealing, extension and denaturation to produce a product mixture which is analyzed by electrophoresis.
摘要:
Sequencing of a selected region of a target nucleic acid polymer in a genomic DNA sample can be performed in a single vessel by combining the sample with a sequencing mixture containing a primer pair, a thermally stable polymerase such as Thermo Sequenase.TM. which incorporates dideoxynucleotides into an extending nucleic acid polymer at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleotides, nucleotide feedstocks, and a chain terminating nucleotide. The mixture is processed through multiple thermal cycles for annealing, extension and denaturation to produce a product mixture which is analyzed by electrophoresis.
摘要:
Sequencing of a selected region of a target nucleic acid polymer in a natural abundance DNA sample can be performed in a single vessel by combining the sample with a sequencing mixture containing a primer pair, a thermally stable polymerase such as Thermo Sequenase™ which incorporates dideoxynucleotides into an extending nucleic acid polymer at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleotides, nucleotide feedstocks, and a chain terminating nucleotide. The reaction mixture also includes an unconventional nucleotide and an appropriate enzyme for degradation of nucleic acid polymers containing the unconventional nucleotide. The mixture is processed through multiple thermal cycles for annealing, extension and denaturation to produce a product mixture which is analyzed by electrophoresis.
摘要:
Sequencing of a selected region of a target nucleic acid polymer in a natural abundance DNA sample can be performed in a single vessel by combining the sample with a sequencing mixture containing a primer pair, a thermally stable polymerase such as Thermo Sequenase™ which incorporates dideoxynucleotides into an extending nucleic acid polymer at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleotides, nucleotide feedstocks, and a chain terminating nucleotide. The reaction mixture also includes an unconventional nucleotide and an appropriate enzyme for degradation of nucleic acid polymers containing the unconventional nucleotide. The mixture is processed through multiple thermal cycles for annealing, extension and denaturation to produce a product mixture which is analyzed by electrophoresis.
摘要:
A method is provided for simultaneously determining the positions of a selected nucleotide base in a target region of both strands of a denatured duplex nucleic acid polymer. The nucleic acid polymer is combined with a reactant mixture comprising first and second oligonucleotide primers, said primers binding to the sense and antisense strands, respectively, of the nucleic acid polymer at a location flanking the target region; a thermostable DNA polymerase; a chain-terminating nucleotide triphosphate complementary to the selected nucleotide base; and other reagents for synthesis of chain extension products to form a reaction mixture. This mixture is processed through a plurality of thermal cycles, each including at least a chain extension phase and a denaturation phase to produce chain extension products. These chain extension products are evaluated to determine the positions of the selected bases. The method of the invention differs from the prior art, because the first and second oligonucleotide primers are each labeled with different, spectroscopically-distinguishable fluorescent labels. The method therefore obtains information about both DNA strands simultaneously while providing improved sensitivity as a result of the non-linear increase in the amount of DNA which results from the production of additional templates molecules from unterminated fragments.
摘要:
Evaluation of a sample for the presence and qualitative nature of a microorganism can be performed in a single vessel by combining a natural abundance DNA sample with a sequencing mixture containing a primer pair, a thermally stable polymerase such as ThermoSequenase™ which incorporates dideoxynucleotides into an extending nucleic acid polymer at a rate which is no less than about 0.4 times the rate of incorporation of deoxynucleotides, nucleotide triphosphate feedstocks, and a chain terminating nucleotide triphosphate. The mixture is processed through multiple thermal cycles for annealing, extension and denaturation to produce a product mixture which is analyzed by electrophoresis.
摘要:
Samples are tested for mutations in the BRCA1 gene using a hierarchical approach. First, each sample is amplified in one or more multiplex PCR amplification reactions. Each multiplex PCR reaction produces a mixture of amplified fragments. The sizes and amounts of these fragments are evaluated and compared to standard values reflecting the sizes and amounts of fragments produced when the same multiplex amplification is performed on the wild-type BRCA1 gene. Differences between the observed fragment sizes and/or amounts and those for the wild-type gene are indicative of a mutation with the BRCA1 gene of the sample. Next, one or more of the exons of the BRCA1 gene are sequenced, preferably only for those samples where no mutation was detected by analysis of the multiplex PCR fragments. The sequencing procedure can be performed by amplification and sequencing of the multiplex amplification mixture.
摘要:
An apparatus and method for thermally cycling a reaction mixture in a reaction vessel to expose the mixture to the varying temperatures necessary to, for example, achieve PCR amplification or the preparation of sequencing fragments using a cycle sequencing operation makes use of flow-through reaction vessels, such as capillary tubes, for the preparation and thermal cycling of reaction mixtures. In order to prevent loss of the reaction mixture from the vessels during heating, the thermal cycling apparatus of the invention provides means for sealing the proximal and distal end of each reaction vessel. The proximal ends can be sealed by coupling to a pump which permits movement of the samples within the reaction vessels. As to the distal ends, the reaction vessels can be sealed by pressing the distal end of each vessel against a sealing element with a conformable surface, or by immersing the distal end of each vessel in the reservoir of liquid, preferably of an oil, that is not miscible with the reaction mixture.
摘要:
The allelic type of a polymorphic genetic locus in a sample is identified by first combining the sample with a sequencing reaction mixture containing a polymerase, nucleotide feedstocks, one type of chain terminating nucleotide and a sequencing primer to form a plurality of oligonucleotide fragments of differing lengths, and then evaluating the length of the oligonucleotide fragments. As in a standard sequencing procedure, the lengths of the fragments indicate the positions of the type of base corresponding to the chain terminating nucleotide in the extended primer. Instead of performing and evaluating four concurrent reactions, one for each type of chain terminating nucleotide, however, the sample is concurrently combined with at most three, and preferably only one, sequencing reaction mixtures containing different types of chain terminating nucleotides. The information obtained from this test is evaluated prior to performing any additional tests on the sample. In many cases, evaluation of the positions of only a single base using one sequencing reaction will allow for allelic typing of the sample.