FARR assay

Methods for detection of anti-dsDNA include immunofluorescence, hemagglutination, radioimmunoassay (RIA), and enzyme-linked immunoassay (ELISA). Different methods may result in discrepant results due to the heterogeneous nature of the antibodies (S20). Numerous studies that compare methods conclude that no single test is perfect. It may be necessary to combine different methods for both higher sensitivity and higher specificity. The most commonly used methods for detecting anti-dsDNA are the CLIF test, the Farr assay, and the ELISA test. 

W10. Werle, E., Blazek, M., and Fiehn, W., The clinical significance of measuring different anti-dsDNA antibodies by using the Farr assay, an enzyme immunoassay and a Chrithidia luciliae immunofluorescence test. Lupus 1, 369—377 (1992). 

The column technique has been applied to lymphocytes from non-im-munized mice as well (Wigzell and Makela, 1970). A mixture of normal lymph node, spleen and bone-marrow cells was passed through an OA-coated column. Column passed cells as well as control cells were transferred to lethally irradiated mice (10 cells per mouse) and followed by immunization with OA and BSA. The antibody content in the sera was detected by the Farr assay. There was no response to OA, while the response to BSA was normal. Control cell suspensions which were not subjected to the column passage resulted in a good response to both OA and BSA (Table 5). 

SR005 Vela Navarrete, R., ]. V. Garcia Cardoso, A. Barat, F. Manzarbeitia, and A. Lopez Farre. BPH and inflammation pharmacological effects of Permixon on histological and molecular inflammatory markers. Results of a double blind pilot clinical assay. Eur Urol 2003 44(5) 549-555. 

Farre, M., M. Kuster, R. Brix, et al. 2007. Comparative study of an estradiol enzyme-linked immunosorbent assay kit, liquid chromatography-tandem mass spectrometry, and ultra performance liquid chromatography-quadrupole time of flight mass spectrometry for part-per-trillion analysis of estrogens in water samples. J. Chromatogr. A 1160 166-175. 

Farre, M., J. Ramon, R. Galve, et al. 2006. Evaluation of a newly developed enzyme-linked immunosorbent assay for determination of linear alkyl benzenesulfonates in wastewater treatment plants. Environ. Sci. Technol. 40 5064—5070. 

Nunes, G.S., M.P. Marco, M. Farre, et al. 1999. Direct application of an enzyme-linked immunosorbent assay method for carbaryl determination in fruits and vegetables. Comparison with a liquid chromatography-postcolumn reaction fluorescence detection method. Anal. Chim. Acta 387 245-253. 

Farre, M., M.J. Garcia, L. Tirapu, A. Ginebreda, and D. Barcelo. 2001. Wastewater toxicity screening of non-ionic surfactants by Toxalert and Microtox bioluminescence inhibition assays. Anal. Chim. Acta 427 181-189. 

In order to obtain information on the specificity of the response and the nature of the metabolite, Amos et al. (1978) modified the experiment by using radiolabel-led human serum albumin instead of the red cell antibody. This enabled a Farr-type assay to be developed (Farr 1958), in which a number of model compounds could be tested for their ability to inhibit the reaction. Figure 8 shows the results of the inhibition studies. It can be deduced from the figure that compounds with an intact or slightly modified isopropanolamine side chain failed to inhibit the interaction of antibody with the metabolite, whereas compounds in which the AT-acetyl-amino function was altered inhibited the response even though the side chain remained exposed. 

Farre, M. et al.. Pesticide toxicity assessment using an electrochemical biosensor with Pseudomonas putida and a bioluminescence inhibition assay with Vidrio fischeri. Anal. Bioaml. Chem., 373, 696, 2002. 

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