Effect of antibody density on the displacement kinetics of a flow immunoassay. Academic Article uri icon

abstract

  • This study investigates the effect of antibody density on the kinetics of a solid-phase displacement immunoassay. Conducted in flow under nonequilibrium conditions, the assay utilizes a monoclonal antibody to the cocaine metabolite benzoylecgonine, which has been immobilized onto Sepharose beads and saturated with fluorophore labeled antigen. Displacement of antibody-bound labeled antigen by non-labeled antigen occurs when sample is introduced in the buffer flow. Comparison of matrices coated with two different antibody densities revealed that the displacement efficiency is a function of the density of antibody-bound labeled antigen. A higher density of antibody provides a higher amount of displaced labeled antigen, but the displacement efficiency of the assay is decreased. The effect of antibody density on the immunoassay kinetics was analyzed using a mathematical formulation developed to characterize antibody-antigen interactions at solid-liquid interfaces. Higher antibody density proved to be associated with a lower apparent dissociation rate constant. The implications of these results on the design of immunoassays in flow are discussed.

published proceedings

  • J Immunol Methods

author list (cited authors)

  • Rabbany, S. Y., Kusterbeck, A. W., Bredehorst, R., & Ligler, F. S.

citation count

  • 32

complete list of authors

  • Rabbany, SY||Kusterbeck, AW||Bredehorst, R||Ligler, FS

publication date

  • February 1994