摘要:
This invention provides a novel rhodium-ruthenium catalyst composition which is adapted for highly selective conversion of synthesis gas to acetic acid and related oxygenated two-carbon hydrocarbon derivatives.
摘要:
A process for making high specific viscosity copolymers of maleic anhydride and an alkyl vinyl either having as specific viscosity of at least 7, preferably 10-50, are made by copolymerizing maleic anhydride and an alkly vinyl ether monomers in the presence of added acetylene.
摘要:
In an extensive Matched Ion Polynucleotide Chromatography (MIPC) system and method, and the computer programs or software associated therewith, the system provides automated options for sample selection, mobile phase gradient selection and control, column and mobile phase temperature control, and fragment collection for a wide variety of MIPC separation processes. MIPC separation processes can be applied to effect size-based separation of DNA fragments, mutation detection, DNA fragment purification, PCR process monitoring and other novel processes. This invention is directed to the system and software which automates many of these procedures, facilitating use of the system to achieve complex separation methods. In one embodiment of the invention, a user specifies a size range of double stranded DNA fragment(s) in a mixture, the software calculates a solvent gradient to elute the fragment(s), and the system performs the chromatographic separation using the calculated gradient. In an embodiment useful in DNA mutation detection, a user specifies the base sequence of a wild type DNA molecule, the software calculates a temperature for partially denaturing heteroduplex and homoduplex molecules of the DNA in a mixture, the software calculates a solvent gradient to elute the fragments, and the system performs the chromatographic separation using the calculated gradient and temperature.
摘要:
In one aspect, the invention provides a method for separating a mixture of polynucleotides, such as DNA or RNA, including (a) applying the mixture to a polymeric separation medium having non-polar surfaces, wherein the surfaces are characterized by being substantially free from multivalent cations, such as metal ions, which are free to interfere with polynucleotide separation, and (b) eluting the mixture with a mobile phase containing organic solvent and counter ion agent. In the separation of single-stranded polynucleotides, improved separation is obtained at a temperature effective to fully denature secondary structure within the polynucleotides.
摘要:
The present invention describes a method for separating or partially separating heteroduplex and homoduplex DNA molecules in a mixture. In the method, the mixture is applied to an anion-exchange chromatography medium. The heteroduplex and homoduplex molecules are eluted with a mobile phase containing an eluting salt, including an anion and a cation, a buffer, and preferably including an organic solvent. The eluting is carried out under conditions effective to at least partially denature the heteroduplexes (e.g., thermal or chemical denaturing) resulting in the separation of the heteroduplexes from the homoduplexes. The method has many applications including, but not limited to, detecting mutations and comparative DNA sequencing.
摘要:
A batch process for obtaining polynucleotide fragments, such as dsDNA, having a selected size from a mixture of polynucleotide fragments including the steps of a) applying a solution of the mixture of polynucleotide fragments and a counterion agent to a binding medium having a hydrophobic surface; b) contacting the binding medium with a first stripping solvent and counterion agent, the first stripping solvent having a concentration of organic component sufficient to release from the binding medium all polynucleotide fragments having a size smaller than the selected size, and removing the first stripping solvent from the binding medium; and c) contacting the binding medium with a second stripping solvent having a concentration of organic component sufficient to release from the binding medium the polynucleotide fragments having the selected size, and removing the second stripping solvent from the binding medium. The binding medium can be organic polymer or inorganic particle beads. The mixture of polynucleotides can be the product of a PCR amplification. The binding medium can be contained within a column, a web or a container.
摘要:
The present invention is directed to improved methods for detection of mutations in DNA using Denaturing Matched Ion Polynucleotide Chromatography (DMIPC). The invention includes the following aspects: analysis of PCR amplification products to identify factors that affect PCR replication fidelity; design of PCR primers; selection of an optimal temperature for performing DMIPC; selection of the mobile phase composition for gradient elution; methods for column preparation and maintenance; and methods for preparing polynucleotide samples prior to chromatographic analysis.
摘要:
A batch process for obtaining polynucleotide fragments, such as dsDNA, having a selected size from a mixture of polynucleotide fragments including the steps of a) applying a solution of the mixture of polynucleotide fragments and a counterion agent to a binding medium having a hydrophobic surface; b) contacting the binding medium with a first stripping solvent and counterion agent, the first stripping solvent having a concentration of organic component sufficient to release from the binding medium all polynucleotide fragments having a size smaller than the selected size, and removing the first stripping solvent from the binding medium; and c) contacting the binding medium with a second stripping solvent having a concentration of organic component sufficient to release from the binding medium the polynucleotide fragments having the selected size, and removing the second stripping solvent from the binding medium. The binding medium can be organic polymer or inorganic particle beads. The mixture of polynucleotides can be the product of a PCR amplification. The binding medium can be contained within a column, a web or a container.
摘要:
An apparatus for effecting base pair length separations of DNA fragments by matched ion paired chromatography comprising a separation column containing separation media having non-polar DNA separation surfaces, separation solution supply means, and a separation solution conduit communicating with the separation column and the separation solution supply means, and a cleaning solution valve means positioned in the separation solution conduit for injecting cleaning solution into the separation solution conduit. A process for cleaning the non-polar DNA separation surfaces in the apparatus comprising interrupting the flow of separation solvent with a block of cleaning solution injected into the flow of separation solution passing to the column, the cleaning solution containing agent which removes accumulated residues from the non-polar surface. The cleaning solution can have an alkaline pH and contain a chelating agent such as EDTA.
摘要:
Nonporous beads having an average diameter of about 0.5-100 microns are suitable for chromatographic separation of mixtures of polynucleotides when the beads comprise a nonporous particle which are coated with a polymer or which have substantially all surface substrate groups endcapped with a non-polar hydrocarbon or substituted hydrocarbon group. The beads provide efficient separation of polynucleotides using Matched Ion Polynucleotide Chromatography.