Abstract: The inventive subject matter relates to a method for detecting the presence of a biological substance of interest in a test sample of saliva or oral fluid, comprising combining said test sample with a fluorescence-labeled ligand to said biological substance and detecting a change in the fluorescence polarization of said test sample produced by binding of said fluorescence-labeled ligand to said biological substance. In one aspect of the inventive subject matter, said method comprises additional steps for comparing the fluorescence polarization of said test sample with the fluorescence polarization of a control solution. Also provided is a miniaturized, portable apparatus for measuring the fluorescence polarization of a liquid sample.

Abstract: The inventive subject matter relates to a competitive method for estimating the concentration in a sample of a Bacillus anthracis protein or antibody thereof selected from the group consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). The method may employ the use of Fluorescence Polarization, FLT or FRET. The competitive methods are capable of detecting a target protein within 5 minutes within the range of 0.1 to 10.0 nM. The methods provide for the rapid detection and quantitation of bacteria, bacterial antigen or antibody in culture media or broth of growing cultures of bacteria, including B. anthracis by fluorescent methods.

Abstract: The inventive subject matter relates to a method for detecting the presence of a biological substance of interest in a test sample of saliva or oral fluid, comprising combining said test sample with a fluorescence-labeled ligand to said biological substance and detecting a change in the fluorescence polarization of said test sample produced by binding of said fluorescence-labeled ligand to said biological substance. In one aspect of the inventive subject matter, said method comprises additional steps for comparing the fluorescence polarization of said test sample with the fluorescence polarization of a control solution. Also provided is a miniaturized, portable apparatus for measuring the fluorescence polarization of a liquid sample.

Abstract: A recombinant, refolded non-fusion polypeptide expressed from a truncated r56 gene of the causative agent of scrub typhus, Orientia tsutsugamushi for the Karp, Kato and Gilliam strains has been produced. The invention is useful for detecting prior exposure to scrub typhus, screening for and/or identification of at least one infectious strain-similarity (i.e. a Karp-like, Kato-like or Gilliam-like strain) based on its strength of reaction toward a truncated protein and as a component in vaccine formulations and production of immune globulins for passive prophylaxis and immunity in subjects.

Abstract: The invention relates to a method for the detection of prior exposure to Coxiella. burnetii infection by antibody-based assays using recombinant, immunodominant C. burnetii polypeptides. The invention also relates to the design of biotin or His-tagged C. burnetii proteins useful in the antibody-based assays as standardized antigen reagents.