the primary goal of this contract is to obtain a rigorous side by side comparison of enzyme linked immuno sorbent assay (elisa) and ord's evanescent wave immunoassay (ew) systems. half way into the contract we have found that when the chemistry of coupling reagents onto the solid phase is identical for both systems, i.e. when fibers are used as the solid phase for both elisa and ew systems, at this early stage of development the ew system already has a small sensitivity advantage over the elisa system. we believe that even equal sensitivity is very exciting since the ew system has a much greater potential for field and bedside use being quicker, more compact and easier to use. unfortunately, at this time the chemistry for coupling reagents onto microtiter wells (as commonly used in elisa) is much more fully developed than the chemistry for coupling to fibers. for this reason a standard elisa using microtiter wells gives a sensitivity between 5 and 10 times better than is achievable using ew. the secondary goal of this contract is to improve ew performance and to this end we are focusing on improving coupling chemistry for the fibers