Abstract: An immunoassay process is provided for the detection of a target antigen in a fluid sample where an admixture of the target antigen and a labeled capture reagent against the target antigen is contacted by a solid polymeric carrier having bound to a portion of its surface a capture reagent against the target antigen and visual determination of a change in color of the bound labeled reaction product on the surface of the solid carrier member serves to readily detect the presence of the target antigen.