Immunoassay analytical elements containing vanadium IV(V+4)ions

摘要

A dry immunoassay analytical element, for assaying a ligand, comprising a support bearing: (a) a labeled ligand zone; (b) a spreading zone; and (c) a receptor zone containing a fixed concentration of an immobilized receptor for the ligand and the labeled ligand and the receptor is covalently bonded to polymeric beads having a diameter in the range of 0.1 to 5 mu m; characterized in that the element contains a compound containing a vanadium IV (V+4) ion and the zones can be in the same or separate layers.