Abstract:
The test substance assay method includes (i) obtaining a mixed solution by mixing (a) first dry particles that are modified with first binding substances exhibiting binding properties specific to a test substance, have an average particle size of 100 nm to 200 nm, and have labels, and (b) second dry particles that are modified with second binding substances not exhibiting binding properties specific to the test substance, have an average particle size of 100 nm to 200 nm, and do not have labels with (c) a test sample solution containing the test substance; (ii) applying the mixed solution onto a substrate; (iii) causing the test substance to be trapped in a reaction site on the substrate that has third binding substances having binding properties specific to the test substance or has substances exhibiting binding properties to the first binding substances; and (iv) detecting the test substance.