Assay employing binding pair members on particles and on a filter or membrane.

摘要

An assay method and kit in which particles bearing a first reagent binding pair member (e.g. anti-digoxin antibody) react with a sample such that analyte binding pair member (e.g. digoxin) binds to the first reagent binding pair member. The reaction mixture is then passed through a filter or membrane of pore size sufficient to allow particles to pass through. A second reagent binding pair member (e.g. digoxin-albumin conjugate) is immobilized on the filter or membrane to trap preferentially either particles which have bound analyte binding pair members or particles which have not, leaving the other class of particles to pass through the filter for detection by resistive pulse techniques, by light absorbence or scattering, by enzymatic read-out (when the particles are enzyme-labeled) or otherwise.