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Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium

Description: Previous studies from our laboratory have demonstrated the feasibility of immunoassays for identification and quantification of specific metal ions. Our ultimate goal for this project is to (1) isolate and characterize antibodies that recognize the most mobile form of uranium, UO22+; (2) assemble, test, and validate a new field-portable immunosensor based on these antibodies; (3) prepare new monoclonal antibodies to the primary chelators (EDTA and DTPA) found in DOE wastes.
Date: June 1, 2001
Creator: Blake, Diane A.
Partner: UNT Libraries Government Documents Department

Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium

Description: The goals for the 3-year project period are (1) to test and validate the present uranium sensor and develop protocols for its use at the NABIR Field Research Center; (2) to develop new reagents that will provide superior performance for the present hand-held immunosensor; and (3) to develop new antibodies that will permit this sensor to also measure other environmental contaminants (chromium, mercury, and/or DTPA). Sensor design modifications are underway via international collaborations. New reagents that will provide superior performance for the present hand-held immunosensor are being prepared and tested. New methods have been developed, to produce recombinant forms of metal-specific monoclonal antibodies for use with the sensor. Site-directed mutagenesis experiments are underway to determine the mechanisms of binding. Immunization experiments with sheep and rabbits to develop new recombinant forms of antibodies to metal-chelate complexes (chromium, mercury, and/or DTPA) have been initiated.
Date: June 1, 2003
Creator: Blake, Diane A.
Partner: UNT Libraries Government Documents Department

Final Technical Report - In-line Uranium Immunosensor

Description: In this project, personnel at Tulane University and Sapidyne Instruments Inc. developed an in-line uranium immunosensor that could be used to determine the efficacy of specific in situ biostimulation approaches. This sensor was designed to operate autonomously over relatively long periods of time (2-10 days) and was able to provide near real-time data about uranium immobilization in the absence of personnel at the site of the biostimulation experiments. An alpha prototype of the in-line immmunosensor was delivered from Sapidyne Instruments to Tulane University in December of 2002 and a beta prototype was delivered in November of 2003. The beta prototype of this instrument (now available commercially from Sapidyne Instruments) was programmed to autonomously dilute standard uranium to final concentrations of 2.5 to 100 nM (0.6 to 24 ppb) in buffer containing a fluorescently labeled anti-uranium antibody and the uranium chelator, 2,9-dicarboxyl-1,10-phenanthroline. The assay limit of detection for hexavalent uranium was 5.8 nM or 1.38 ppb. This limit of detection is well below the drinking water standard of 30 ppb recently promulgated by the EPA. The assay showed excellent precision; the coefficients of variation (CV’s) in the linear range of the assay were less than 5% and CV’s never rose above 14%. Analytical recovery in the immunosensors-based assay was assessed by adding variable known quantities of uranium to purified water samples. A quantitative recovery (93.75% - 108.17%) was obtained for sample with concentrations from 7.5 to 20 nM (2-4.75 ppb). In August of 2005 the sensor was transported to Oak Ridge National Laboratory, for testing of water samples at the Criddle test site (see Wu et al., Environ. Sci. Technol. 40:3978-3985 2006 for a description of this site). In this first on-site test, the in-line sensor was able to accurately detect changes in the concentrations of uranium in effluent samples from ...
Date: July 5, 2006
Creator: Blake, Diane A.
Partner: UNT Libraries Government Documents Department

Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium

Description: Progress Report Date: 01/23/06 (report delayed due to Hurricane Katrina) Report of results to date: The goals of this 3-year project are to: (1) update and successfully deploy our present immunosensors at DOE sites; (2) devise immunosensor-based assays for Pb(II), Hg(II), chelators, and/or Cr(III) in surface and groundwater; and (3) develop new technologies in antibody engineering that will enhance this immunosensor program. Note: Work on this project was temporarily disrupted when Hurricane Katrina shut down the University on August 29, 2005. While most of the reagents stored in our refrigerators and freezers were destroyed, all of our hybridoma cell lines were saved because they had been stored in liquid nitrogen. We set up new tissue culture reactors with the hybridomas that synthesize the anti-uranium antibodies, and are purifying new monoclonal antibodies from these culture supernatants. Both the in-line and the field-portable sensor were rescued from our labs in New Orleans in early October, and we continued experiments with these sensors in the temporary laboratory we set up in Hammond, LA at Southeastern Louisiana University.
Date: January 23, 2006
Creator: Blake, Diane A.
Partner: UNT Libraries Government Documents Department

Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium

Description: A collaborator in the Chemistry Department at Tulane University, Dr. Harry Ensley, has synthesized a new bifunctional chelator with specificity for ionic mercury (Hg2+) and methymercury (MeHg+). These chelators are based upon phenantholine derivative containing sulfhydryl functional groups. Experiments are underway to generate protein conjugates of this chelator to use in immunizations and screening.
Date: June 1, 2005
Creator: Blake, Diane A.
Partner: UNT Libraries Government Documents Department

Detection of hexavalent uranium with inline and field-portable immunosensors

Description: An antibody that recognizes a chelated form of hexavalent uranium was used in the development of two different immunosensors for uranium detection. Specifically, these sensors were utilized for the analysis of groundwater samples collected during a 2007 field study of in situ bioremediation in a aquifer located at Rifle, CO. The antibody-based sensors provided data comparable to that obtained using Kinetic Phosphorescence Analysis (KPA). Thus, these novel instruments and associated reagents should provide field researchers and resource managers with valuable new tools for on-site data acquisition.
Date: October 2, 2008
Creator: Melton, Scott J.; Yu, Haini; Ali, Mehnaaz F.; Williams, Kenneth H; Wilkins, Michael J.; Long, Philip E. et al.
Partner: UNT Libraries Government Documents Department