Abstract: Disclosed are methods for detecting or quantifying one or more target polynucleotide sequences in a sample. In one aspect, a sample is contacted with first and second probe pair that are capable of hybridizing to a selected target sequence and a corresponding complementary sequence, respectively. Probe cleavage and ligation results in the formation of ligation products which can be generated in an exponential fashion when the target sequence and/or complement are present in the sample. In another embodiment, a single probe pair can be used to form ligation product in a linear fashion from a complementary template. Reagents and kits are also disclosed.

Abstract: The invention provides a method for reducing stutter in the amplification of a microsatellite comprising the steps of providing a sample comprising a microsatellite having a G+C content of greater than 50%; contacting the sample with at least one enzyme having nucleic acid polymerase activity; and incubating the sample with the enzyme for a sufficient amount of time and under conditions sufficient to amplify the microsatellite; wherein the incubation is performed in the presence of an amount of sorbitol effective to reduce stutter relative to the amount of stutter observed in the absence of sorbitol. The invention also provides compositions containing sorbitol, kits for amplifying microsatellites having a G+C content of greater than 50%, and methods of using all of the foregoing.

Abstract: Disclosed are methods for detecting or quantifying one or more target polynucleotide sequences in a sample. In one aspect, a sample is contacted with first and second probe pair that are capable of hybridizing to a selected target sequence and a corresponding complementary sequence, respectively. Probe cleavage and ligation results in the formation of ligation products which can be generated in an exponential fashion when the target sequence and/or complement are present in the sample. In another embodiment, a single probe pair can be used to form ligation product in a linear fashion from a complementary template. Reagents and kits are also disclosed.

Abstract: A capillary electrophoresis system and method of electrokinetically loading a capillary electrophoresis sample into a separation medium in a capillary tube in which an entangled polymer matrix is formed having the sample embedded therein. The matrix has a mesh size effective to retard movement of macromolecules such as DNA sequencing templates through the matrix when an electric field is applied across the matrix. The entangled polymer matrix is formed by a linear polymer having a molecular weight of at least 20K Daltons. Furthermore, the invention includes stable denaturants useful for the electrophoresis of nucleic acids.

Abstract: Apparatus and method for performing a nucleic acid amplification reaction and preferably a polymerase chain reaction (PCR) in a reaction mixture in at least one capillary tube. Several different embodiments are disclosed. One embodiment cycles a sample through a capillary tube loop passing through two thermostatted fluid baths. Another embodiment has the capillary tube routed alternatingly between two heat exchangers to that the sample makes only one pass through the tube. Other embodiments maintain the heat exchangers stationary and translate the samples between them. Still further embodiments maintain the samples stationary and either automatically translate or rotate the heat exchangers past the samples contained within the capillary tubes to perform the thermal cycles necessary for the amplification reaction.

Abstract: Improved methods, compositions and kits for detecting mutations in nucleic acids are disclosed, such comprise annealing a piece of control nucleic acid without mutations to a piece of test nucleic acid very similar in sequence to the control nucleic acid but possibly containing mutations, treating this mixture with potassium permanganate or hydroxylamine to remove mismatched bases from the duplex nucleic acid, treating the resulting nucleic acid with any of a class of diamines, triamines, and tetraamines analogous to 1,2-ethylenediamine to cleave abasic sites, and then analyzing the chemically treated nucleic acid to determine whether cleavage has occurred and approximately at what position in the nucleic acid any cleavage has occurred. Inclusion of betaine in the base-removal reactions improves their sensitivity and specificity.

Abstract: A capillary electrophoresis system and method of electrokinetically loading a capillary electrophoresis sample into a separation medium in a capillary tube in which an entangled polymer matrix is formed having the sample embedded therein. The matrix has a mesh size effective to retard movement of macromolecules such as DNA sequencing templates through the matrix when an electric field is applied across the matrix. The entangled polymer matrix is formed by a linear polymer having a molecular weight of at least 20K Daltons. Furthermore, the invention includes stable denaturants useful for the electrophoresis of nucleic acids.

Abstract: Solvents for salt-gradient anion-exchange separation of nucleic acids, especially double-stranded DNA and especially by liquid chromatography, are improved by replacing NaCl as the eluting salt with any of a wide range of alkyl ammonium salts and can be used to elute nucleic acids in strict order of increasing length, with reduced sensitivity to elution temperature and salt concentration. Anion-exchange chromatography with these solvents is well suited for identification of DNA fragments on the basis of size, with greater accuracy, precision, and resolvable size range than often is possible with gel electrophoresis.

Abstract: Solvents for salt-gradient anion-exchange separation of nucleic acids, especially double-stranded DNA and especially by liquid chromatography, are improved by replacing NaCl as the eluting salt with any of a wide range of alkyl ammonium salts and can be used to elute nucleic acids in strict order of increasing length, with reduced sensitivity to elution temperature and salt concentration. Anion-exchange chromatography with these solvents is well suited for identification of DNA fragments on the basis of size, with greater accuracy, precision, and resolvable size range than often is possible with gel electrophoresis.

Abstract: Apparatus and method for performing a nucleic acid amplification reaction and preferably a polymerase chain reaction (PCR) in a reaction mixture in at least one capillary tube. Several different embodiments are disclosed. One embodiment cycles a sample through a capillary tube loop passing through two thermostatted fluid baths. Another embodiment has the capillary tube routed alternatingly between two heat exchangers to that the sample makes only one pass through the tube. Other embodiments maintain the heat exchangers stationary and translate the samples between them. Still further embodiments maintain the samples stationary and either automatically translate or rotate the heat exchangers past the samples contained within the capillary tubes to perform the thermal cycles necessary for the amplification reaction.

Abstract: Apparatus and method for performing a nucleic acid amplification reaction and preferably a polymerase chain reaction (PCR) in a reaction mixture in at least one capillary tube. Several different embodiments are disclosed. One embodiment cycles a sample through a capillary tube loop passing through two thermostatted fluid baths. Another embodiment has the capillary tube routed alternatingly between two heat exchangers to that the sample makes only one pass through the tube. Other embodiments maintain the heat exchangers stationary and translate the samples between them. Still further embodiments maintain the samples stationary and either automatically translate or rotate the heat exchangers past the samples contained within the capillary tubes to perform the thermal cycles necessary for the amplification reaction.

Abstract: Apparatus and method for performing a nucleic acid amplification reaction and preferably a polymerase chain reaction (PCR) in a reaction mixture in at least one capillary tube. Several different embodiments are disclosed. One embodiment cycles a sample through a capillary tube loop passing through two thermostatted fluid baths. Another embodiment has the capillary tube routed alternatingly between two heat exchangers to that the sample makes only one pass through the tube. Other embodiments maintain the heat exchangers stationary and translate the samples between them. Still further embodiments maintain the samples stationary and either automatically translate or rotate the heat exchangers past the samples contained within the capillary tubes to perform the thermal cycles necessary for the amplification reaction.

Abstract: Improvements to the polymerase chain reaction (PCR), a process for in vitro enzymatic amplification of specific nucleic acid sequences, can be achieved by changing the way that PCR reagents are mixed and the enzymatic reaction is started and by the replacement of mineral oil, commonly used as a vapor barrier to minimize solvent evaporation, by a grease or wax. The use of such mixtures allows for the delay of reagent mixing until the first heating step of a PCR amplification, thereby reducing the enzymatic generation of nonspecific products which occurs when a complete mixture of PCR reagents, with or without test sample, stands at room temperature or below. These mixtures increase the shelf-life of PCR reagents and increase protection of the laboratory environment against contamination by PCR product.

Abstract: Improvements to the in situ polymerase chain reaction (PCR), a process of in vitro enzymatic amplification of specific nucleic acid sequences within the cells where they originate, can be achieved by changing the way that the enzymatic reaction is started. Reaction initiation is delayed until the start of PCR thermal cycling, either by withholding a subset of PCR reagents from the cellular preparation until the preparation has been heated to 50.degree. C. to 80.degree. C., immediately before thermal cycling is begun, or by adding to the PCR reagents a single-stranded DNA binding protein which blocks reaction at temperatures below about 50.degree. C. If the in situ PCR is performed on cellular preparations already attached to a microscope slide, thermal cycling also is facilitated by use of a thermal cycler sample block or compartment designed optimally to hold the microscope slide and any vapor barrier covering the slide.

Abstract: Improvements to the polymerase chain reaction (PCR), a process for in vitro enzymatic amplification of specific nucleic acid sequences, can be achieved by changing the way that PCR reagents are mixed and the enzymatic reaction is started and by the replacement of mineral oil, commonly used as a vapor barrier to minimize solvent evaporation, by a grease or wax. The use of such mixtures allows for the delay of reagent mixing until the first heating step of a PCR amplification, thereby reducing the enzymatic generation of nonspecific products which occurs when a complete mixture of PCR reagents, with or without test sample, stands at room temperature or below. These mixtures increase the shelf-life of PCR reagents and increase protection of the laboratory environment against contamination by PCR product.

Abstract: Xylose isomerase (XI) muteins useful in the conversion of glucose to fructose or xylose to xylulose are obtained in usable amounts by protein structural and recombinant DNA methods, including x-ray crystallography, cloning, computer graphic modeling and site-directed mutagenesis and expression of the bacterial DNA sequences encoding native procaryotic xylose isomerase. These native sequences are altered to encode the xylose isomerase muteins having improved catalytic function and/or thermostability.

Abstract: The invention herein is directed to methods using Procion dyes to perform separations of interest in manipulating the NAD.sup.+ -independent ribotoxins. The methods are useful for preparing therapeutic agents containing these ribotoxins or their A polypeptide components. This separation method has been applied in particular to preparing hybrid toxins containing ricin toxins, both for purifying the resulting products and also for separating the components intended to be used in the preparation of these end products. In addition, a novel ricin isotoxin prepared using the method of the invention is disclosed.

Abstract: The invention herein is directed to methods using Procion dyes to perform separations of interest in manipulating the NAD.sup.+ -independent ribotoxins. The methods are useful for preparing therapeutic agents contaning these ribotoxins of their A polypeptide components. This separation method has been applied in particular to preparing hybrid toxins containing ricin toxins, both of purifying the resulting products and also for separating the components intended to be used in the preparation of these end products. In addition, a novel ricin isotoxin prepared using the method of the invention is disclosed.

Abstract: Useful for visualizing biological materials in a solid phase, on a gel, or in a liquid phase is a solid salt of the meriquinone of benzidine or a substituted benzidine. An immobilized or dissolved complex of a polymeric anion and the meriquinone of benzidine or a substituted benzidine having controllable solubility may also be employed. Preferred are meriquinone salts and complexes of 3,3,5,5'-tetramethylbenzidine. For visualization, the benzidine or substituted benzidine is oxidized to its meriquinone at pH 3 to 7 in the presence of an effective anion or polymeric anion, an oxidation catalyst, and an effective amount of oxidant to form a solid salt or immobilized complex of the meriquinone under conditions where the meriquinone solubility lies below about 10.sup.-5 M.