BTG Plc., a world leader in the commercialisation of novel technologies operate from offices in the UK, North America and Japan has recently acquired the latest technology of fibre optic immunoassay sensor from Empirical Technologies Corporation (ETC) Inc. The company is currently seeking to license companies capable of commercialising this technology, which provides a sensitive detector with a wide variety of applications in the fields of biology, biochemistry and chemistry, as well as in many clinical applications.

The single mode fibre optic immunoassay sensor technology is based on a coupled pair of fibre optic fibres, which are used as an immunoassay device. The fibres are first coupled and then drawn down to a single mode diameter. The coupler senses output ratio change due to the chemical, biochemical, bioaffinity or immunogenic interactions of bio-molecules (ligands) with their respective binding partners.

Either of the binding partners is permanently attached to the fusion joint of a single mode coupler within the evanescent field for specific and direct detection of minute concentrations of an analyte of interest within the tested sample without the need to label a reagent. The biomolecule may be linked to the surface of the fusion joint by means of a spacer molecule.

The key features of this technology includes high sensitivity, effects of phase and intensity noise on systems sensitivity addressed, The evanescent field surrounds the entire space immediately around the core, the single mode fibre optic coupler operates at low spatial mode without speckle and the inexpensive coupler device.

The sensor has a broad range of application in the use of in vitro diagnostics in the fields of biology, biochemistry, chemistry and medicine. These applications have the potential for use in mainstream laboratory immunoassay or to be incorporated into hand-held devices for the point of care use in hospitals, physicians'' offices or in the home. They include detection of minute quantities of bioaffinity binding pairs, such as antigen-antibody, substrate-enzyme, binding protein-nucleic acid etc., binding of nucleotides using the principles of solution hybridisation, binding of single stranded oligonucleotides will allow detection of complimentary DNA or RNA. This application could be used for evaluation of levels of mRNA expression in tissues, detection of Viral DNA''s and forensic science and also for environmental detection of airborne pathogens.