摘要:
A method for obtaining information about the allelic type of a sample of genetic material derived from an HIV-infected sample relies on the observation that using a second nested set of sequencing primers ensures the maximum potential for sequencing a particular sample. To perform the method, reagents suitable for performing the tests are suitably packaged as a kit.
摘要:
A streamlined, hierarchical method for obtaining information about the allelic type of a sample of genetic material derived from an HIV-infected sample relies on the observation that 93-95% of the known mutational variants of the reverse transcriptase and protease genes of HIV-1 can be determined by evaluating the positions of the A and T nucleotides within the sample. Thus, a substantial fraction of all mutational variations can be unequivocally identified by performing two initial sequencing reactions on the sample in which only ddA and ddT are used as chain terminators. For the small fraction of samples which are not identifiable based on the positions of these two bases, a second test is performed in which the sequence is determined in the 3'-direction for all four bases. This test will identify substantially all of the remaining samples. For those for which an ambiguity remains, however, a final test in which the sequence of the sample is determined in both the 3' and 5-direction for all four bases is performed. To perform the method, reagents suitable for performing the three tests within the hierarchy are suitably packaged as a kit containing two or more sub-kits. The first sub-kit contains reagents for performing A and T sequencing. The additional sub-kits contains reagents for performing a four-base sequence determination on one or both strands of the target DNA.
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 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:
A device for retaining a sheath of a remote control via cable has an attachment molded integrally with a support. The attachment has a base part arising from the support to delimit a housing for accommodating a fitting of the sheath, as well as a cover linked to the base part by a film hinge, in such a way that the cover is able to pivot between an opening position for the insertion of the fitting and a locking position for trapping the fitting. In the position for locking the cover, the end fitting is held in the housing, being immobilized axially and free in rotation.
摘要:
A method for obtaining information about the allelic type of a sample of genetic material derived from an HIV-infected sample relies on the observation that using a second nested set of sequencing primers ensures the maximum potential for sequencing a particular sample. To perform the method, reagents suitable for performing the tests are suitably packaged as a kit.
摘要:
A rotary electrical switch for panel mounting in a motor vehicle for control of a blower motor of a heating, ventilating and/or air conditioning installation, includes a set of conductive contact strips. These comprise coplanar primary strips and a secondary strip for power supply. The switch has a body mounted for rotation about an axis at right angles to the plane of the coplanar contact strips. The body supports a radial ring member which is bent back into two half rings with conductive radial projecting portions connected together electrically. Each projecting portion carries at its end an arm having two contact pads for making contact with the primary contact strips in two parallel planes. The projecting portions have at least one third pad for making a further contact with the secondary contact strip in one of the two planes.
摘要:
A method for quantitative and qualitative analysis of a nucleic acid analyte in a sample suspected to contain the nucleic acid analyte first combines the sample with a control nucleic acid, and two primer pairs, a first primer pair effective to amplify a conserved region of the nucleic acid analyte if present in the sample to produce a conserved fragment having a first length and to amplify the control nucleic acid to produce a control fragment having a second length different from the first length, and a second primer pair effective to amplify a second region of the nucleic acid analyte to produce a sequencing fragment. One member of the first primer pair is labeled with a detectable label, and one member of the second primer pair may be labeled with a label such as biotin effective to permit capture of the primer. The combined mixture is then processed to amplify the sample and control nucleic acid using the first and second primer pairs to produce an amplification product mixture containing conserved fragments, sequencing fragments and control fragments when the nucleic acid analyte is present in the sample, and only control fragment when the nucleic acid analyte is not present in the sample. This product mixture is analyzed to determine the relative amounts of conserved fragments and control fragments in the amplification product mixture to quantify the amount of nucleic acid analyte in the sample and used as a starting point for a reaction to determine the sequence of the sequencing fragment.