DISPERSED METAL PARTICLE LABELLED ASSAY

A method, test kit and labeled component for the detection and/or determination of one or more components of the reaction between a specific binding protein and the corresponding bindable substance, in which one or more labelled components are used, that are obtained by coupling particles of a dispersion of a metal, metal compound or polymer nuclei, coated with a metal or metal compound, having a particle size of at least 5 nm, directly or indirectly to the desired component of said reaction. During the reaction or after an adequate reaction time, the physical properties and/or the amount of the metal and/or the formed metal containing agglomerate, is/are determined in the test sample, or optionally after a separation of the bound and free metal-labelled components in one of the derived fractions by methods known as known by those skilled in the immunoassay field.