Characterization of monoclonal anti-furosemide antibodies and molecular modeling studies of cross-reactive compounds.

Four mouse monoclonal antibodies directed against furosemide have been isolated and characterized. The cross-reactivity of the antibodies with eight compounds which are structurally and/or functionally related to furosemide was determined using a competition ELISA. All of the compounds, including furosemide, were then modeled using molecular mechanical and quantum mechanical methods in an attempt to correlate antibody binding with the conformational and electronic properties of the molecules. The results of these experiments demonstrated that all of the cross-reactivity observed could be readily explained using these techniques. Furthermore, these results should allow for more accurate prediction of unexpected cross-reactivities with these antibodies when they are used in immunoassays for determination of furosemide.