Abstract: 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.

Abstract: 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.

Abstract: A Matched Ion Polynucleotide Chromatography method and system for size-based segregation of a mixture of RNA molecules. The method includes applying the mixture to a polymeric separation medium having non-polar surfaces and eluting the RNA molecules with a mobile phase which includes counterion reagent and an organic component. The preferred surfaces are characterized by being substantially free from multivalent cations which are free to interfere with RNA segregation. The elution is preferably performed at a temperature sufficient to denature the RNA. The method can be used in segregating RNA molecules having lengths in the range of about 100 to 20,000 nucleotides. Improved segregation is obtained using a chromatography column having an ID greater than about 5 mm. Examples of separation media include beads and monolithic columns.

Abstract: 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.

Abstract: In one aspect, the invention provides a computer implemented method for transforming a plurality of chromatographic elution profiles, wherein each profile is obtained from the separation of a mixture of homoduplex and heteroduplex molecules by Denaturing Matched Ion Polynucleotide Chromatography. The method preferably includes overlaying the profiles; adjusting the baseline by applying a slope factor to each detector response value so that all of the profiles share a common baseline; normalizing the heights of the peaks to a scale of 1; and shifting the profiles along the x-axis so that all of the profiles intersect at a pre-selected point. In another aspect, the invention provides a method for applying statistical criteria to the transformed profiles to determine whether they represent more that one group. In yet another aspect, the invention concerns methods for grouping the profiles based on their shapes.

Abstract: The present invention relates to improvements in methods of DNA mutation detection using chromatographic methods such as DHPLC. In particular, the invention relates to methods for increasing the level of heteroduplex during a hybridization process between a DNA fragment and a corresponding wild type DNA fragment by including during the hybridization process nitrogen-containing organic compounds such as betaine, trimethylamine N-oxide, and dimethylglycine. In another aspect the invention provides improved PCR primers for amplifying the DNA to be used in the hybridization. The invention also provides for DNA hybridization kits containing these compounds and primers.

Abstract: 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.

Abstract: Covalently bound non-polar tags are used to increase the retention times of double stranded polynucleotides on Matched Ion Polynucleotide Chromatography (MIPC) columns. In doing so, separations of DNA mixture components is improved. Additionally, when the non-polar tags are fluorophores, detection limits are also greatly reduced. Strategically tagged primers are used in conduction with PCR to produce DNA fragments having specifically tagged strands. This improves mutation detection by MIPC in several ways. Separations are improved, detection sensitivity is enhanced, and non-stoichiometric addition of wild type DNA prior to hybridization is now possible since only tagged fragments will be observed with a fluorescence detector. Non-polar tags are also used as a novel alternative to G-C clamping during MIPC under partially denaturing conditions. Reversible DNA binding dyes, such as DNA intercalator dyes and DNA groove binding dyes, are used to reduce the detection limit of polynucleotides separated by MIPC.

Abstract: 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.

Abstract: Non-polar polymeric separation media, such as beads or monoliths, are suitable for chromatographic separation of mixtures of polynucleotides when the surfaces of the media are unsubstituted or substituted with a hydrocarbon group having from one to 1,000,000 carbons and when the surfaces are substantially free from mutivalent cation contamination. The polymeric media provide efficient separation of polynucleotides using Matched Ion Polynucleolide Chromatography. Methods for maintaining and storing the polymeric media include treatment with multivalent cation binding agents.

Abstract: 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.

Abstract: The present invention provides a method for calibrating a MIPC column wherein the calibration relates to the determination of the organic solvent component in the mobile phase required to elute dsDNA fragments of different base pair lengths at specific retention times. Since a MIPC column affords highly reproducible separations, once calibrated, the base pair length of unknown dsDNA fragments can be determined by comparing their retention times to those obtained on a standard calibration chromatogram. The standard calibration chromatogram is obtained by chromatographing a standard dsDNA ladder containing fragments of known base pair length. In addition, a method is provided to determine the presence of nicks in dsDNA using MIPC under fully denaturing conditions, e.g., 80° C. In one embodiment, this method is applied to the detection of mutations in dsDNA.

Abstract: A method for removing a target DNA fragment having a predetermined base-pair length from a mixture of DNA fragments comprises the following steps. A mixture of DNA fragments which may contain the target DNA fragments is applied to a separation column containing media having a nonpolar, nonporous surface, the mixture of DNA fragments being in a first solvent mixture containing a counterion and a DNA binding concentration of driving solvent in a cosolvent. The target DNA fragments are separated from the media by contacting it with a second solvent solution containing a counterion and a concentration of driving solvent in cosolvent which has been predetermined to remove DNA fragments having the target DNA fragment base pair length from the media. The target DNA fragments can be collected and optionally amplified. When the method is being applied to collect a putative fragment, if present, no DNA fragments having the base pair length of the target DNA could be present in the mixture.

Abstract: 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.

Abstract: 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.

Abstract: Non-polar polymeric separation media, such as beads or monoliths, are suitable for chromatographic separation of mixtures of polynucleotides when the surfaces of the media are unsubstituted or substituted with a hydrocarbon group having from one to 1,000,000 carbons and when the surfaces are substantially free from mutivalent cation contamination. The polymeric media provide efficient separation of polynucleotides using Matched Ion Polynucleotide Chromatography. Methods for maintaining and storing the polymeric media include treatment with multivalent cation binding agents.

Abstract: 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.

Abstract: 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.

Abstract: Mixtures of dsDNA fragments are separated by Matched Ion Polynucleotide Chromatography (MIPC) using an isocratic mobile phase to elute polynucleic acid from an MIPC column. The use of isocratic elution conditions provides a marked improvement in the separation of dsDNA fragments compared to gradient elution conditions. Isocratic elution can also be used to effect an improved separation of heteroduplex and homoduplex mixtures when the chromatography is performed under partially denaturing conditions. In addition, dsDNA fragments are bound to the stationary phase under isocratic conditions until a solvent concentration is reached which releases fragments of a particular base pair length range. This separation process is different from the equilibrium partitioning process observed under gradient elution conditions.

Abstract: The present invention provides a method for calibrating a MIPC column wherein the calibration relates to the determination of the organic solvent component in the mobile phase required to elute dsDNA fragments of different base pair lengths at specific retention times. Since a MIPC column affords highly reproducible separations, once calibrated, the base pair length of unknown dsDNA fragments can be determined by comparing their retention times to those obtained on a standard calibration chromatogram. The standard calibration chromatogram is obtained by chromatographing a standard dsDNA ladder containing fragments of known base pair length. In addition, a method is provided to determine the presence of nicks in dsDNA using MIPC under fully denaturing conditions, e.g., 80° C. In one embodiment, this method is applied to the detection of mutations in dsDNA.