摘要:
Various methods are described that provide for high resolution melt (HRM) genotyping. The embodiments include providing a locus specific primer and two allele specific primers each having a 5′ end with a short tail, providing a nucleic acid having a single nucleotide polymorphism (SNP) base located within 1-20 base pairs of the 3′ end of nucleic acid, hybridizing the locus specific primer and the allele specific primers to the nucleic acid, amplifying the sample using pyrophosphorolysis activated polymerization (PAP) PCR enzyme, and determining the Tm of the amplicons using HRM. In other embodiments, reactions mixtures and kits for HRM genotyping are provided and disclosed. These kits comprise a locus specific primer, one or more allele specific primers each having a 5′ end with a short tail, a nucleic acid, and a pyrophosphorolysis activate polymerization (PAP) PCR enzyme.
摘要:
The invention provides novel nucleic acid polymerases from strains GK24 and RQ-1 of Thermus thermophilus, and nucleic acids encoding those polymerases, as well as methods for using the polymerases and nucleic acids.
摘要:
In various embodiments, the present teachings provide sequencing methods which facilitate enhancing the efficiency of ligation and/or increasing sequencing reads. Various embodiments of the methods enable sequencing through template regions for which complementary labeled extension probes are unavailable or insufficient. In various embodiments, one or more rounds of ligation with unlabeled extension probes can be used in addition to a round of ligation with labeled extension probe. In various embodiments, for example, such methods can facilitate extension on template polynucleotides that do not bind labeled extension probe in the first round of ligation.
摘要:
The present invention provides methods for determining a nucleic acid sequence by performing successive cycles of duplex extension along a single stranded template. The cycles comprise steps of extension, ligation, and, preferably, cleavage. In certain embodiments the methods make use of extension probes containing phosphorothiolate linkages and employ agents appropriate to cleave such linkages. The invention provides methods of determining information about a sequence using at least two distinguishably labeled probe families. In certain embodiments the methods acquire less than 2 bits of information from each of a plurality of nucleotides in the template in each cycle. In certain embodiments the sequencing reactions are performed on templates attached to immobilized beads. The invention further provides sets of labeled probes containing phosphorothiolate linkages. In addition, the invention includes performing multiple sequencing reactions on a single template by removing initializing oligonucleotides and extended strands and performing subsequent reactions using different initializing oligonucleotides.
摘要:
The present teachings provide methods, compositions, and kits for synthesizing and sequencing nucleic acids. In some embodiments, elaborated nucleotide phosphorothiolate compounds are employed along with efficient cleaving reactions. Improved sequencing efficiency is achieved by the rapid polymerase-mediated incorporation of elaborated nucleotide phosphorothiolate compounds. Increased sequencing efficiency is also achieved by the ability of the cleaving reactions to restore the incorporated nucleotides to their natural structure prior to subsequent elongation.
摘要:
Methods of modifying a nucleophilic surface of a support are described. The methods involve reacting a multifunctional electrophilic reagent with nucleophilic groups on the surface of the support. The resulting electrophilic surface can be used for the covalent attachment of particles (e.g. beads) having nucleophilic functional groups. For example, nucleic acid templates with nucleophilic (e.g., amine) groups can be attached to a surface of the particles. The nucleophilic groups on the nucleic acid templates can then be used to attach the particles to the modified surface of the support. The resulting support-bound particles can be used to analyze (e.g., sequence) the nucleic acid templates on the particles.
摘要:
Fluorescent phenyl xanthene dyes are described that comprise any fluorescein, rhodamine or rhodol comprising a particular C9 phenyl ring. One or both of the ortho groups on the lower C9 phenyl ring is ortho substituted with a group selected from alkyl, heteroalkyl, alkoxy, halo, haloalkyl, amino, mercapto, alkylthio, cyano, isocyano, cyanato, mercaptocyanato, nitroso, nitro, azido, sulfeno, sulfinyl, and sulfino. In one embodiment, halo and/or hydroxy groups are used. Optimal dyes contain a lower C9 phenyl ring in which both ortho groups are the same and the lower ring exhibits some form a symmetry relative to an imaginary axis running from the phenyl rings point of attachment to the remainder of the xanthene dye through a point para to the point of attachment. The phenyl xanthene dyes may be activated. Furthermore, the phenyl xanthene dyes may be conjugated to one or more substances including other dyes. The phenyl xanthene dyes are useful for a number of purposes, including labels for use in automated DNA sequencing as well the formation of fluorescent “bar codes” for polymeric particles used in the multiplexed analysis of analytes.
摘要:
System and method for fluorescent light excitation and detection from samples to enhance the numerical aperture and/or reduce the cross-talk of the fluorescent light.
摘要:
An instrument for performing highly accurate PCR employing an assembly, a heated cover, and an internal computer, is provided. The assembly is made up of a sample block, a number of Peltier thermal electric devices, and a heat sink, clamped together. A control algorithm manipulates the current supplied to thermoelectric coolers such that the dynamic thermal performance of a block can be controlled so that pre-defined thermal profiles of sample temperature can be executed. The sample temperature is calculated instead of measured using a design specific model and equations. The control software includes calibration diagnostics which permit variation in the performance of thermoelectric coolers from instrument to instrument to be compensated for such that all instruments perform identically. The block/heat sink assembly can be changed to another of the same or different design. The assembly carries the necessary information required to characterize its own performance in an on-board memory device, allowing the assembly to be interchangeable among instruments while retaining its precision operating characteristics.
摘要:
A multi-well microfiltration apparatus and method are provided and feature a manual touch-off system for transferring pendent drops hanging from discharge-conduits of a discharge-conduit array to respective receiving wells or receiving holes of a corresponding receiving array, with minimum or no cross-contamination between the discharge conduits, or the receiving wells or receiving holes. The manual touch-off is achieved by manually shifting a carriage that supports one of the arrays, into a position whereat pendent drops of fluid hanging from the distal ends of the discharge conduits contact the inner sidewalls of the corresponding receiving wells or receiving holes of the receiving array.