Abstract: Novel expression vectors are provided for expressing a fusion glycoprotein. The fusion glycoprotein contains the N-terminal globular domain of a retroviral env surface protein linked to a selected glycopeptide. Truncation glycoproteins as well as insertion glycoproteins are expressed using the vectors.

Abstract: Unimolecular and bimolecular hybridization probes for the detection of nucleic acid target sequences comprise a target complement sequence, an affinity pair holding the probe in a closed conformation in the absence of target sequence, and either a label pair that interacts when the probe is in the closed conformation or, for certain unimolecular probes, a non-interactive label. Hybridization of the target and target complement sequences shifts the probe to an open conformation. The shift is detectable due to reduced interaction of the label pair or by detecting a signal from a non-interactive label. Certain unimolecular probes can discriminate between target and non-target sequences differing by as little as one nucleotide. Also, universal stems and kits useful for constructing said probes. Also, assays utilizing said probes and kits for performing such assays.

Abstract: A synergistic combination of antibodies specific for HIV envelope glycoprotein gp120 is described. One of the antibodies specific for the V3 loop and the other is specific for the CD-4 binding site of gp120.

Abstract: Nucleic acid sandwich hybridization assays are provided that incorporate one or a combination of background reduction steps. Those steps include use of a separate capture probe and separation from immobilized capture probes by cleavage and isolation. A very sensitive assay for RNA targets includes both of those steps, plus RNA binary probes, an RNA-directed RNA ligase and amplification by an RNA-directed RNA polymerase. Kits of reagents for performing assays according to this invention are also provided.

Abstract: There are provided nucleic acid hybridization assays for RNA targets using RNA binary probes and a ribozyme ligase that is a stringent RNA-directed RNA ligase. Preferred assays include exponential amplification for signal generation. Tetrahymena ribozyme ligase is a preferred ligase for use in this invention. It may be tethered to hold it close to the ligation junction. One assay according to this invention is a "tethered ligase chain reaction." Also provided are kits for performing assays according to the invention.

Abstract: Novel expression vectors are provided for expressing a fusion glycoprotein. The fusion glycoprotein contains the N-terminal globular domain of a retroviral env surface protein linked to a selected glycopeptide. Truncation glycoproteins as well as insertion glycoproteins are expressed using the vectors.

Abstract: Mutant ribozymes are screened by culturing cells whose survival is dependant upon cleavage of RNA by a ribozyme, which cleavage causes the cells to survive in the presence of an agent which otherwise would kill the cells, and selecting cells which survive.

Abstract: A probe for the detection of a nucleic acid target sequence containing a molecular switch comprising three essential elements: a probe sequence of 20-60 nucleotides surrounded by switch sequences of 10-40 nucleotides which are complementary to each other, wherein the state of the switch is useful for selectively generating a detectable signal if the probe is hybridized to a target; also, assays and kits utilizing such probes.

Abstract: The present invention provides recombinant plasmids which is transformant microbial hosts express lysostaphin, a bacteriocin that kills most known staphylococcal species. The invention also provides lysostaphin, substantially free from non-lysostaphin contaminants. Recombinant plasmids, pRG5, pJP1, pDF8 and pRP1, were derived by inserting a 1.5 kilobase segment of DNA coding for lysostaphin into the cloning vectors, pUC8, pBC16, pBD64 and pSPV1, respectively. E. coli strain JM105 transformed by pRG5 and members of Bacillus species, including B. subtilis and B. sphaericus transformed by pJP1, pDF8 and pRP1 produce lysostaphin which is immunologically and electrophoretically indistinguishable from that produced by S. simulans, the natural source. Furthermore, B. sphaericus strain 00/pJP1 transformants produce five times the amount of lysostaphin as S. simulans. The invention also provides the 1.5 kbp DNA fragment coding for lysostaphin.