Clinical specimens and excised samples of diseased tissues may contain various types of proteins. Enzyme-linked immunosorbent assay (ELISA) is a typical method for detecting specific proteins present in minute quantities in such samples.
The immunoconcentration method is known as a fast and simple ELISA method. This method titrates a specimen on a porous film (membrane) on the surface of which an immobilized antibody has been fixed beforehand to produce an antigen-antibody reaction on the membrane. A detection reagent is titrated onto the membrane to produce a color reaction, and then a wash solution is titrated to clarify the color (for example, see: Japanese Laid-Open Patent Nos. H1-223352 and 2000-329766).
When a plurality of items are to be assayed, the preparation of the porous membrane on which an antibody has been previously fixed requires that a number of types of porous membranes or solid-phase plates corresponding to the number of items to be assayed are prepared, thereby reducing assay efficiency.