Abstract: The invention relates to bis-protein-DNA conjugates. A protein having an antigen specific binding activity is covalently linked to each end of a derivatized DNA molecule. The bis-protein-DNA conjugates can be used for immunoassays and measuring distances between proteins at up to 3.4 .ANG. resolution. The invention also relates to methods of synthesizing these bis-protein-DNA conjugates. Synthesis of the conjugates entails derivatizing the 5' or 3' end of a DNA oligonucleotide and covalently linking that DNA to a protein. The DNA can be indirectly conjugated to an antibody or Fab' fragment, using a avidin/streptavidin-biotin linkage. The conjugates of the invention can be used in immunoassays and PCR assays.

Abstract: This invention is directed to methods for determining a nucleotide sequence of a nucleic acid using positional sequencing by hybridization, and to the creation of nucleic acids probes which may be used with these methods. This invention is also directed to diagnostic aids for analyzing the nucleic acid composition and content of biological samples, including samples derived from medical and agricultural sources.

Abstract: The present invention defines a DNA:protein-binding assay useful for screening libraries of synthetic or biological compounds for their ability to bind DNA test sequences. The assay is versatile in that any number of test sequences can be tested by placing the test sequence adjacent to a defined protein binding screening sequence. Binding of molecules to these test sequence changes the binding characteristics of the protein molecule to its cognate binding sequence. When such a molecule binds the test sequence the equilibrium of the DNA:protein complexes is disturbed, generating changes in the concentration of free DNA probe. Numerous exemplary target test sequences (SEQ ID NO:1 to SEQ ID NO:600) are set forth. The assay of the present invention is also useful to characterize the preferred binding sequences of any selected DNA-binding molecule.

Abstract: The invention is directed to constructs and compositions containing multimeric forms of nucleic acid. Multimeric nucleic acids comprise single-stranded nucleic acids attached via biotin to streptavidin and bound with a functional group. These constructs can be utilized in vivo to treat or identify diseased tissue or cells. Repeated administrations of multimeric nucleic acid compositions produce a rapid and specific amplification of nucleic acid constructs and their attached functional groups. For treatment purposes, functional groups may be toxins, radioisotopes, genes or enzymes. Diagnostically, labeled multimeric constructs may be used to identify specific targets in vivo or in vitro. Multimeric nucleic acids may also be used in nanotechnology and to create self-assembling polymeric aggregates such as membranes of defined porosity, microcircuits and many other products.

Abstract: This invention is directed to methods for determining a nucleotide sequence of a nucleic acid using positional sequencing by hybridization, and to the creation of nucleic acids probes which may be used with these methods. This invention is also directed to diagnostic aids for analyzing the nucleic acid composition and content of biological samples, including samples derived from medical and agricultural sources.

Abstract: The invention provides a method for purifying or isolating double stranded DNA intact using triple helix formation. The method includes the steps of complexing an oligonucleotide and double stranded DNA to generate a triple helix and immobilization of the triple helix on a solid phase by means of a molecular recognition system such as avidin/biotin. The purified DNA is then recovered intact by treating the solid phase with a reagent that breaks the bonds between the oligonucleotide and the intact double stranded DNA while not affecting the Watson-Crick base pairs of the double helix. The present invention also provides a method for purifying or isolating double stranded DNA intact by complexing the double stranded DNA with a specific binding partner and recovering the complex during electrophoresis by immobilizing it on a solid phase trap imbedded in an electrophoretic gel.

Abstract: A novel recombinant streptavidin-protein A chimeric protein which allows conjugation of antibody molecules with biological materials. The chimeric protein is efficiently expressed in Escherichia coli and is purified by simple procedures. The purified chimetic protein can bind one biotin molecule and one to two immunoglobulin molecules per subunit.

Abstract: The present invention defines a DNA:protein-binding assay useful for screening libraries of synthetic or biological compounds for their ability to bind DNA test sequences. The assay is versatile in that any number of test sequences can be tested by placing the test sequence adjacent to a defined protein binding screening sequence. Binding of molecules to these test sequence changes the binding characteristics of the protein molecule to its cognate binding sequence. When such a molecule binds the test sequence the equilibrium of the DNA:protein complexes is disturbed, generating changes in the concentration of free DNA probe. Also described herein is a method to capture DNA that has been released from the DNA:protein complex.

Abstract: This invention concerns a method for identifying in vitro an animal-infective form of a parasitic protozoan which comprises recovering total mRNA from the protozoan and detecting in the mRNA so recovered the presence of a mRNA transcript encoding a heat shock protein associated with animal-infective parasitic protozoans, which transcript is present only in the animal-infective form of the protozoan, or quantitatively determining in the mRNA so recovered the number of a mRNA transcript encoding a heat shock protein associated with animal-infective parasitic protozoans, which transcript is present in increased number only in the animal-infective form of the parasitic protozoan.This invention also concerns a method for identifying an agent capable of blocking the formation of the animal-infective form of a parasitic protozoan.

Abstract: The present invention provides a compound having the formula ##STR1## wherein Y is biotin or iminobiotin, X is CH.sub.2, P is psoralen or a psoralen derivative, r is an integer equal to or greater than 2 and s is an integer equal to or greater than 1.The invention also provides a method for preparing a biotinylated psoralen or a biotinylated psoralen derivative.Further provided are methods for detecting, purifying, and isolating nucleic acids, and methods for delivering an iminobiotinylated psoralen to a cell.

Abstract: Gel inserts comprising a solidified liquid such as agarose suitable for use in an electrophoretic method, lysed cells entrapped within a matrix formed by the solidified liquid and macromolecules such as DNA or intact chromosomes derived from the lysed cells may be advantageously used in electrophoretic separations. The gel inserts are placed directly in a suitable support medium and subjected to one or more electric fields to separate the macromolecules.

Abstract: DNA which encodes the polypeptide streptavidin has been isolated as a fragment 2 kb in length derived from a restriction endonuclease digestion of the chromosomal DNA of Streptomyces avidinii. The nucleic acid sequence of the gene and the amino acid sequence of the polypeptide have been determined. A fused gene has been prepared which comprises the streptavidin gene fused to a gene encoding the human LDL receptor. Expression of the gene fusion results in a fused streptavidin-human LDL receptor polypeptide. Methods are provided for using the fused gene to produce labeled, chemically modified proteins in vivo and to isolate a protein knowing only the nucleotide sequence of the gene encoding the protein.

Abstract: Gel inserts comprising a solidified liquid such as agarose suitable for use in an electrophoretic method, lysed cells entrapped within a matrix formed by the solidified liquid and macromolecules such as DNA or intact chromosomes derived from the lysed cells may be advantageously used in electrophoretic separations. The gel inserts are placed directly in a suitable support medium and subjected to one or more electric fields to separate the macromolecules.

Abstract: Disclosed are an apparatus for and a method of electrophoretically separating particles by electric fields which are transverse to each other, which alternate between respective high and low intensities out of phase with each other at a frequency related to the mass of the particles and which move the particles in an overall direction transverse to the respective directions of the fields. For separating large macromolecules, at least one of the fields preferably has an intensity gradient in a direction transverse to its own. The new arrangement makes it possible to: (1) separate particles (molecules) larger in size than those able to be separated with previously known techniques, (2) carry out separation at higher speed and at better resolution than is possible with previously known techniques, and (3) concurrently separate particles which differ greatly in mass (molecular weight).