title: Analysis of vesicle immunolysis assays. The direct binding model.
abstract: Assays based on lysis of lipid vesicles have shown high sensitivity. However, little as yet is known about the quantitative relationships among the various assay parameters, due in part to the lack of a predictive theoretical model. This paper presents the derivation of the equations that describe a simple model assay system in terms of the total fraction of vesicles with bound antibodies and the distribution of vesicles with one, two, or more antibodies bound. The equations show how the binding of antibodies to vesicles is affected by such variables as: vesicle concentration, antigen density on vesicle surfaces, antibody concentration, and antibody affinity. With the distribution functions, experiments can be designed to determine the minimum number of antibodies needed to lyse a vesicle. In addition, it is shown how estimations of the ultimate sensitivity of lipid vesicle lytic assays can be made. The model can be used to optimize vesicle lysis assay systems.
mesh_terms: D000937:Antigen-Antibody Reactions; D005453:Fluorescence; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008954:Models, Biological
chemical_list: D007140:Immunoglobulin Fab Fragments