Patent ID: 7951610

Claim:
A reaction method of performing an adsorption reaction in which a subject substance of analysis is specifically adsorbed in a wall of a first channel, the method comprising: flowing a specimen liquid into a second channel that flows said specimen liquid into the first channel which is connected to the second channel so that the specimen liquid is fed to the first channel from the second channel, the specimen liquid containing the subject substance of analysis and a labeled substance that can be bonded to the subject substance of analysis; stopping feeding of the specimen liquid by detecting an event that an entire specimen liquid flows into the first channel; feeding a washing liquid after the specimen liquid such that a space is not generated between the two liquids by flowing the washing liquid to a third channel that is made to feed into the first; and feeding the washing liquid to the first channel from the third channel after the washing liquid is joined the specimen liquid, wherein a narrowed section is provided in the first channel, the narrowed section being continued from a connection portion of the first channel to the second channel, a sectional area a of the narrowed section is set smaller than a sectional area A of the second channel, and the event that the entire rear end of the specimen liquid flows into the first channel is detected based on a change in internal pressure of the first channel.