The long range goal of this research is to develop a device incorporating and assay for simple, quick, reliable, accurate, and highly sensitive measurements of compounds in human saliva. Phase I feasibility research is focused on development of the solid phase assay portion with progesterone as the prototypic analyte. The primary application of the progesterone assay will be for the assessment of fertility status in women (follicular vs. luteal phase of the menstrual cycle vs. pregnancy). Technologies resulting from development of the proposed product will also provide the basis for adapting the assay to other biological media (e.g. equine, bovine, and porcine saliva) to facilitate economic domestic animal breeding and, with different antibodies, to detect other substances. The initial assay will utilize an existing, highly specific monoclonal antibody to progesterone. When used in a solid phase assay, this antibody has proven to give accuate esimates of progesterone in blood plasma. The system being proposed will be evaluated and optimized with radiolabeled indicator but highly sensitive alternatives for a colorimetric assay meeting the same quality criteria will be explored and implemented in parallel as progress allows. The unique collection/assay device to be developed in Phase II is designed to remove food particles, eliminate problems with endogenous salivary mucins, and rapidly yield readily visualizable colorimetric differences. Once feasibility of the approach is proven, separate projects will be undertaken to adapt the technology to quantitation of other compounds and agents (e.g. street drugs, corticoids, toxins and therapeutic drugs).