ELEMENT FOR IMMUNOASSAY AND PROCESS OF USING THE SAME

An element for immunoassay or quantitative analysis of an immunoreactive analyte contained in an aqueous liquid sample is provided. The element comprises a first matrix for retaining a carrier so that the carrier is not released in the aqueous liquid sample. In the case where the immunoreactive analyte is an antigen, an antibody for the analyte antigen is immobilized by the carrier; and where the immunoreactive analyte is an antibody, the specific antigen for the analyte antibody is immobilized by the carrier. A further essential component is a second matrix for retaining a marker-labelled antigen for the case where the analyte is antigen so that the marker-labelled antigen is retained firmly until the second matrix contacts with an aqueous medium and is released rapidly when the second matrix contacts with the aqueous medium for the analyte. Where the analyte is an antibody, the second matrix retains a marker-labelled antibody in the same manner. The element for immunoassay of the invention may be used for the purpose of quantitative analysis of a variety of immunoreactive materials while utilizing competitive antigen-antobody reactions or some other ways to provide dry system throughout the analytical operations. Also provided is a process for quantitative analysis of an analyte antigen or antibody by the combined use of a photometrical or colorimetrical measurement with the element for immunoassay of the invention.