Abstract: A bio-spectral imaging system and methods for in situ diagnosis of a disease state in biological tissue or cells of a living organism are provided. In one form, a method includes applying to the tissue or cells in situ a biological stain composition that includes at least one metachromatic dye; performing a spectral analysis to obtain at least one spectrum of the stained tissue or cells; comparing the spectrum with spectra from a library of spectra of similarly stained reference tissue or cells that have been categorized as diseased or non-diseased; and correlating the spectrum to a disease state. The system and methods may be used to diagnose, for example, pre-cancer and/or cancer, as well as diseases caused by various microorganisms. Methods for creating a library of spectra, methods for monitoring the efficiency of photodynamic therapy of diseased biological tissue or cells in vivo, as well as methods for improving the efficiency of photodynamic therapy are also provided.

Abstract: A method is disclosed where one or more biological stains are applied to living tissue displaying, or suspected of having cells, or parts of the tissue which are diseased, metaplasic, or otherwise abnormal, including but not limited to lesions which may be thought pre-cancerous or cancerous. The stained tissue is then analyzed, in situ, by reflectance spectroscopy, the results of which are then compared to a digital library of reflectance spectrums of such tissue that have been previously diagnosed by conventional histochemical techniques. The method is further disclosed as a means to monitor the progress of photodynamic therapy using the same biological stains as specific photosensitizers.

Abstract: A biological stain composition contains toluidine blue O and a pharmaceutically acceptable oxidizing agent to convert any leuco toluidine blue O to the chromo form. A dry composition for preparing the stain includes the toluidine blue O, the oxidizing agent and an effervescent agent. These compositions are preferably buffered to improve shelf stability and clinical consistency. Compositions for intra-oral application contain a flavoring agent.

Abstract: A device for detecting the presence of a predetermined reactant in a fluid suspected of containing the same which comprises a pyroelectric film having a first and a second surface, a first electrode in contact with a portion of the first surface of said pyroelectric film, a second electrode in contact with a portion of the first surface of said pyroelectric film, said first and said second electrodes being proximate to but electrically insulated from each other, an infra-red transparent third electrode having a first and second surface, said first surface being in contact with the second surface of said film, methods of making such a device and methods of utilizing same.

Abstract: There is provided a novel method of testing for the presence of an analyte in a fluid suspected of containing the same. In this method, in the presence of the analyte, a substance capable of modifying certain characteristics of the substrate is bound to the substrate and the change in these qualities is measured.While the method may be modified for carrying out quantitative differential analyses, it eliminates the need for washing analyte from the substrate which is characteristic of prior art methods.

Abstract: A method, sensor and semiconductor device for determining the concentration of an analyte in a medium. The device features an element constructed of semiconductive organic polymer associated with a binding substance having specific affinity for the analyte.

Abstract: A method, sensor and semiconductor device for determining the concentration of an analyte in a medium. The device features an element constructed of polyacetylene associated with a binding substance having specific affinity for the analyte.

Abstract: Addition of a low concentration of an alkali metal metabisulfite completely stops color development in a peroxidase-labeled immunoassay wherein the peroxidase catalyzed reaction comprises oxidation of an achromatic substrate to the corresponding chromatic product in the presence of a peroxide.

Abstract: A method for determining the presence of a ligand in a liquid medium which utilizes enzyme labeled avidin and biotin labeled reagent in a specific binding process wherein the ligand to be detected is contacted with an insoluble phase containing specific binding substance for the ligand. Various protocols may be used to assay the resulting enzyme activity which is related to the amount of ligand in the liquid medium.