Abstract: This invention relates to a method of incorporating an exo-sample nucleotide into the amplified product strands resulting from a nucleic acid amplification process. Once the product strands have been obtained and analyzed (e.g., by hybridization, Southern blot, etc.), the exo-sample strands can be selectively destroyed by acting on the incorporated exo-sample nucleotide. Two embodiments are presented. In a first embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an excess of exo-sample nucleotide triphosphate. In a second embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an oligonucleotide which has, as part of its sequence, one or more exo-sample nucleotides.

Abstract: Recombinational cloning is provided by the use of nucleic acids, vectors and methods, in vitro and in vivo, for moving or exchanging segments of DNA molecules using engineered recombination sites and recombination proteins to provide chimeric DNA molecules that have the desired characteristic(s) and/or DNA segment(s).

Abstract: Recombinational cloning is provided by the use of nucleic acids, vectors and methods, in vitro and in vivo, for moving or exchanging segments of DNA molecules using engineered recombination sites and recombination proteins to provide chimeric DNA molecules that have the desired characteristic(s) and/or DNA segment(s).

Abstract: Recombinational cloning is provided by the use of nucleic acids, vectors and methods, in vitro and in vivo, for moving or exchanging segments of DNA molecules using engineered recombination sites and recombination proteins to provide chimeric DNA molecules that have the desired characteristic(s) and/or DNA segment(s).

Abstract: Recombinational cloning is provided by the use of nucleic acids, vectors and methods, in vitro and in vivo, for moving or exchanging segments of DNA molecules using engineered recombination sites and recombination proteins to provide chimeric DNA molecules that have the desired characteristic(s) and/or DNA segment(s).

Abstract: Particles such as bacteria may be enumerated from a liquid in an accurate and efficient manner through use of an apparatus including a filter sheet which is oriented transverse to the surface of the liquid being filtered. The filter sheet is so arranged so that, as the liquid is filtered, an increasing portion of the filter is above the surface of the liquid. As a result of the surface of the liquid dropping across the filter, a smaller fraction of the total volume of the liquid passes through the upper portion of the filter than through the lower portion of the filter. Since the number of bacteria trapped per unit area of the filter depends on the volume filtered through the area, a monotonically increasing gradient of density of filtered bacteria occurs from the top to the bottom of the filter.

Abstract: This invention relates to a method of incorporating an exo-sample nucleotide into the amplified product strands resulting from a nucleic acid amplification process. Once the product strands have been obtained and analyzed (e.g., by hybridization, Southern blot, etc.), the exo-sample strands can be selectively destroyed by acting on the incorporated exo-sample nucleotide. Two embodiments are presented. In a first embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an excess of exo-sample nucleotide triphosphate. In a second embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an oligonucleotide which has, as part of its sequence, one or more exo-sample nucleotides.

Abstract: Recombinational cloning is provided by the use of nucleic acids, vectors and methods, in vitro and in vivo, for moving or exchanging segments of DNA molecules using engineered recombination sites and recombination proteins to provide chimeric DNA molecules that have the desired characteristic(s) and/or DNA segment(s).

Abstract: The invention relates to a nucleic acid marker ladder which is a restriction endonuclease digest, wherein a nucleic acid restriction endonuclease digest is a collection of nucleic acid fragments resulting from complete digestion of one or more nucleic acids by one or more restriction endonucleases; the restriction endonuclease digest contains at least 3 fragments; and the size of the fragments in base pairs is a multiple of an integer, wherein the integer is 10 or more.

Abstract: This invention relates to a method of incorporating an exo-sample nucleotide into the amplified product strands resulting from a nucleic acid amplification process. Once the product strands have been obtained and analyzed (e.g., by hybridization, Southern blot, etc.), the exo-sample strands can be selectively destroyed by acting on the incorporated exo-sample nucleotide.Two embodiments are presented. In a first embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an excess of exo-sample nucleotide triphosphate.In a second embodiment, the exo-sample nucleotide is incorporated by carrying out the amplification reaction in the presence of an oligonucleotide which has, as part of its sequence, one or more exo-sample nucleotides.

Abstract: The invention relates to a multidomain protein comprising sites for cleavage of the protein into at least 3 polypeptide domains; nucleic acid encoding the multidomain protein; a protein ladder comprising a collection of protein fragments obtained by the partial cleavage of one or more multidomain proteins by one or more cleaving agents; and methods of using and preparing the protein ladder.

Abstract: Methods and recombinant vectors suitable for accomplishing the in vivo alteration of a nucleic acid molecule are disclosed. The invention in particular discloses the use of recombinases such as Cre to accomplish in vivo recombination.

Abstract: Apparatus and method for radiographic inspection of welds, which welds may be seal welds of the kind typically found on nuclear power reactor control rod drive mechanisms (CRDMs). Such CRDM seal welds seal the threaded joint defined by a generally tubular pressure housing and a generally tubular vessel head adapter, the housing and adapter enclosing the CRDM components. The apparatus comprises a circular track capable of surrounding and being connected to the vessel head adapter. A radiation source assembly capable of emitting penetrating radiation and a radiation shielding assembly capable of shielding against the radiation are mounted on the track. The assemblies are adjustable for aligning the assemblies with the seal weld. A radiographic film is interposed between the radiation source assembly and the radiation shielding assembly and adjacent the weld for capturing a volumetric image of the weld on the film.

Abstract: According to this invention, a process for substantially amplifying template nucleic acid present in a sample is described, wherein said amplification may be performed without prior knowledge of specific sequences, which process comprises apposition of random oligonucleotide primers to said template nucleic acid under conditions such that extension products of said primers are synthesized which are complementary to said template nucleic acid.

Abstract: According to this invention, a process for substantially amplifying template nucleic acid present in a sample is described, wherein said amplification may be performed without prior knowledge of specific sequences, which process comprises apposition of random oligonucleotide primers to said template nucleic acid under conditions such that extension products of said primers are synthesized which are complementary to said template nucleic acid.

Abstract: In the process according to this invention, an amplification procedure is performed on a first sample in which one or more of the four normal ribonucleoside triphosphates (rNTPs) or deoxyribonucleoside triphosphates (dNTPs) is replaced with an exo-sample nucleotide. After amplification, any contaminating amplified product that may be remaining is subjected to a physical, chemical, enzymatic, or biological treatment which renders nucleic acid containing the exo-sample nucleotide substantially unamplifiable. The treatment may be done as a separate step or it may be done in the presence of a second sample containing nucleic acid sequences to be amplified. The amplified nucleic acid sequences derived from the first sample which contaminate the second sample are not further substantially amplified during amplification of nucleic acid sequences of the second sample.

Abstract: A process for detecting specific nucleotide sequences, called targets, in which a special DNA probe molecule, called a probe-vector, is capable of transforming bacteria if and only if it is held in a circular configuration by base pairing to a target nucleic acid, said transformation resulting in the detection of a phenotype specified by the probe-vector, said detection establishing the presence, absence, or quantity of the target; and a probe-vector molecule for performing the process.

Abstract: Genetic reagents for generating plasmids containing multiples of a DNA segment are prepared by modification of the restriction sites of plasmid rings. The modified plasmids permit cloning of DNA segments which can be recovered with sticky ends that are complementary but not rotationally equivalent. Such segments will polymerize in a head-to-tail conformation. The plasmid rings with modified restriction sites are also used in linear form to obtain head-to-tail joining of multiple DNA segments into plasmid rings for further cloning and/or expression of the DNA segment-directed protein. The critical restriction site sequences of the modified plasmid rings can be prepared as a reagent which permits the sequence to be introduced into any plasmid. The reagents have utility in preparing multiples of protein-forming genes, and in preparing large amounts of homogeneous DNAs which can themselves be used as reagents.