Literature Search - Detailed Result A TEF-Based Dioxin Kit Utilizing Fluorescent Aptamers (EPA 2006 SBIR Phase 1) Investigator: Bharat Chandramouli, (919) 281-4040 Company: Eno River Labs, LLC, Durham, NC Contract Information: EPD06031 Period of Performance: March 1, 2006 through August 31, 2006 SBIR Funds: March 1, 2006 through August 31, 2006 Abstract: Eno River Labs, LLC, (ERL) proposes to develop an onsite testing kit for dioxins that uses fluorescently tagged ssDNA aptamers for selective binding and subsequent screening and quantitative analysis of dioxin in soil sample. Current dioxin field test kits are immunoassay-based, which are insufficiently specific and sometimes unreliable. Reliable dioxin testing requires laboratory tests, which can take days to weeks for results. The field test kit will provide rapid and easy to use for on-site quantitative testing for dioxin contamination. The kit will be based on the use of aptamers, which are specific binding nucleic acids that can be engineered to bind almost any compound with specificity and reliability. Aptamer mixes also can be designed to have different affinities to the different analytes of interest, hence a toxicity equivalency factor (TEF)-scaled kit is possible. In Phase I, ERL proposes to generate a set of specific fluorescent DNA aptamers to bind 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the dioxin with the highest TEF. These dioxin-specific fluorescent aptamers will be developed by the systematic evolution of ligands by exponential enrichment (SELEX) technique. During development, the dioxin-binding aptamers will be tested for their ability to bind specifically to 2,3,7,8-TCDD in the presence of other potential soil contaminants such as polychlorinated biphenyls (PCBs). In Phase II, ERL plans to define the standard curve for 2,3,7,8-TCDD, develop a TEF-scaled aptamer mix to screen for other toxic congeners, develop the quantitative parameters of ERL's kit, apply the dioxin-specific aptamers in a lyophilized form to be easily used in the kit, and demonstrate their utility for contaminated soil monitoring. ERL will test and validate the kit with U.S. EPA Method 1613B, using archived soil samples and performing the analysis in-house, thus obviating the need for field sampling. ERL's kit will be the first truly TEF-based kit available and will be useful for quick analysis onsite, thus providing a means of contamination monitoring, potential reduction in business risk, and more educated decision on modification in construction plans. ERL's onsite kit will offer a nontoxic environmentally friendly, fast, reliable test for dioxin contamination in soil.