Abstract: Nucleic acid hybridization probes having at least one nucleic acid strand which has at least two separate target specific regions that hybridize to a target nucleic acid sequence, and at least two distinct arm regions that do not hybridize with the target nucleic acid but possess complementary regions that are capable of hybridizing with one another. These regions are designed such that, under appropriate hybridization conditions, the complementary arm regions will not hybridize to one another in the absence of the target nucleic acid; but, in the presence of target nucleic acid the target-specific regions of the probe will anneal to the target nucleic acid, and the complementary arm regions will anneal to one another, thereby forming a branched nucleic acid structure.

Abstract: In an assay for a target nucleotide sequence employing hybridization with a target probe nucleotide sequence, cross reaction between the target probe and a non-target nucleotide sequence, capable of hybridizing with the target probe, is prevented or diminished by introducing, at some point during the hybridization, a non-target probe which hybridizes preferentially with the non-target nucleotide sequence. The melting temperature for the non-target probe/non-target nucleotide sequence hybrid is preferably greater than that of the target probe/non-target sequence hybrid. The hybridization can be carried out under isothermal conditions or preferentially with gradual cooling.

Abstract: Nucleic acid hybridization probes having at least one nucleic acid strand which has at least two separate target specific regions that hybridize to a target nucleic acid sequence, and at least two distinct arm regions that do not hybridize with the target nucleic acid but possess complementary regions that are capable of hybridizing with one another. These regions are designed such that, under appropriate hybridization conditions, the complementary arm regions will not hybridize to one another in the absence of the target nucleic acid; but, in the presence of target nucleic acid the target-specific regions of the probe will anneal to the target nucleic acid, and the complementary arm regions will anneal to one another, thereby forming a branched nucleic acid structure.

Abstract: A versatile polymeric support system for the synthesis of oligonucleotides is provided featuring a universal primer which allows chain elongation, in either the 3' or 5' direction, with any currently available DNA or RNA synthesis method, by a process which utilizes oxidatively cleaved primers to facilitate chain elongation and release. The support system is capable of withstanding mildly basic and acidic reaction conditions, while still permitting a convenient and quantitative release, either before or after removal of protecting groups from reactive groups, of synthesized oligonucleotides from a single polymeric support. Removal of the protecting groups before cleavage of the oligomer from the support permits the use of the immobilized oligomer as an affinity hybridization support for both isolating and detecting complementary polynucleic acids.

Abstract: Improved homogenous diagnostic assay methods and labels for detecting an analyte in a medium when the analyte is a member of a specific binding pair. The methods and labels provide procedures for reducing background and increasing sensitivity. The binding partner of the analyte is labeled with a substance, the stability of which detectably changes whenever said analyte is bound as a member of the specific binding pair. In a closely related system, the analyte is labeled with a substance susceptible to differential degradation depending on whether or not the analyte is bound as a member of its specific binding pair. After incubation and selective degradation or chemical or biochemical alteration, the amount of analyte bound is detected by measuring either the stability change or the extent of degradation of the label.

Abstract: Methods for the construction, labelling and subsequent purification of nucleic acid probes containing primary amines with acridinium esters 4-(2-succinimidyloxycarbonyl-ethyl)phenyl-10-methylacridinium-9-carboxylat e fluorosulfonate). The method for attaching acridinium esters to probes uses high (0.1 to 50 mM) acridinium ester concentrations achieved using organic solvent in concentrations of 20% to 80% by volume, and may be carried out either in solution, or with one or the other of the acridinium ester or the probe suspended in solution. Purification (the separation of labelled probe from unlabelled probe and free label) involves (1) first removing most of the free acridinium ester label from probe using rapid separation techniques, then (2) removing substantially all remaining free label from the probe and separating labelled probe from unlabelled probe, involves specific applications of ion exchange, reverse phase or hydroxyapatite HPLC.

Abstract: A method of preparing a labelled specific binding partner, such as a biological probe in the form of an antibody or oligonucleotide probe, using a protected label (the corresponding unprotected label being susceptible to inactivation, such as by hydrolysis to yield a non-chemiluminescent form of the label). The specific binding partner is linked to the label, and an adduct of the label is prepared using a protective adduct former which produces a protected label which is less susceptible to inactivation. Particularly preferred labels are the acridiniums and acridans, most preferably the former having the general structure: ##STR1## wherein the phenyl rings are optionally additionally substituted, R.sub.1 is preferably an alkyl, and R.sub.5 is an optionally substituted hydrocarbon, most preferably a phenyl moiety which is either linked to the specific binding partner, or capable of being linked thereto.

Abstract: Prodrug compounds for dermal application of topical medicaments, such as 6-aminonicotinamide for treatment of psoriasis, are linked by an enzyme cleavable group to a carrier side chain, such as succinyl piperidate or morpholidate. The neutral lipophilic compounds are rapidly absorbed into the epithelial cells where they are enzymatically cleaved to release the active drug in an ionic form which is retained within the cells.