An Alternative Chemical Redox Method for the Production of Bispecific Antibodies: Implication in Rapid Detection of Food Borne Pathogens

Abstract

<div><p>Bi-functional antibodies with the ability to bind two unrelated epitopes have remarkable potential in diagnostic and bio-sensing applications. In the present study, bispecific antibodies that recognize human red blood cell (RBC) and the food borne pathogen <i>Listeria monocytogenes</i> (<i>L. monocytogenes</i>) were engineered. The procedure involves initial reduction of a mixture of anti-RBC and anti-Listeria antibodies followed by gradual re-oxidation of the reduced disulphides. This facilitates association of the separated antibody chains and formation of hybrid immunoglobulins with affinity for the <i>L. monocytogenes</i> and human RBC. The bispecific antibodies caused the agglutination of the RBCs only in the presence of <i>L. monocytogenes</i> cells. The agglutination process necessitated the specific presence of <i>L. monocytogenes</i> and the red colored clumps formed were readily visible with naked eyes. The RBC agglutination assay described here provides a remarkably simple approach for the rapid and highly specific screening of various pathogens in their biological niches.</p></div