BioGenex awarded United States patent on the synthesis of branched oligomers for nucleic acid labeling and amplification.

BioGenex Laboratories, Inc. (San Ramon, CA) announced that it has been granted a United States patent relating to multifunctional reagents that can be used to introduce multiple labels or reporter molecules onto oligomers such as oligonucleotides and oligopeptides. United States Patent 5,916,750, entitled "Multifunctional Linking Reagents for Synthesis of Branched Oligomers," was issued on June 29th, 1999, and is the twelfth United States patent assigned to the company.

These modified branching non-nucleoside bases, which BioGenex refers to as "diverge DNA", avoids the problem of non-specific hybridization that is seen with branched DNA signal amplification and detection. Prior methods for linking a label to a nucleotide probe have generally utilized a single label attached to a nucleosidic monomeric unit, and then incorporating one or more of the nucleosidic monomeric units into the probe. Such "linear" labeled nucleotides in a probe, however, can influence the sensitivity of the hybrid formed with a target nucleotide sequence, particularly when multiple labels are present. The current invention solves this problem since it provides reagents capable of linking monomeric units to form branched oligomers.

According to George S. Su, PhD, Manager of R&D Chemistry at BioGenex and a co-inventor of the said patent, "The structure of our branching diverge DNA reduces possible steric hindrance of molecules, thereby providing maximum availability of haptens to bind to a maximum number of enzyme conjugates. These new reagents greatly increase signal amplification of labeled oligonucleotides. Applications include use in in situ hybridization, fluorescent in situ hybridization and other solid-phase assays where strong signal detection and sensitivity are desired."

Krishan L. Kalra, PhD, chairman and CEO of BioGenex and a co-inventor of this patent, added: "This technology can be incorporated into BioGenex's automated immunohistochemistry and special staining system (OptiMax Plus Consolidated Staining System; United States Patent 5,439,649. The diverge DNA probes developed for in situ hybridization have the sensitivity and specificity to amplify the signal-to-noise ratio and thus detect single copy genes in an in situ hybridization format. Undoubtedly, we now have achieved significant progress towards developing a truly automated high-thoughput in situ hybridization assay platform that can be performed at room temperature." An article describing the application of this technology for signal amplification appeared in a recent edition of the journal Biotechnology International.

BioGenex Laboratories develops and commercializes value-added, high-margin histopathology diagnostic reagents and automated instrumentation systems for in situ tissue-based analysis of cancer, infectious disease and genetic disorders. The company is capitalizing on emerging, high-growth market opportunities in clinical diagnostics by applying modern molecular and cellular diagnostic methods to the testing of intact human tissue. This type of diagnostic analysis, termed in situ testing, provides information at the cellular and sub-cellular level. The benefits are accurate and early diagnosis, prognosis, therapeutic selection, and better therapy management to improve disease outcome.