Patent ID: 7393697

Claim:
An immunoassay device for determining the presence of an analyte in a liquid sample, comprising: a buffer receiving member for receiving a buffer solution; a conjugate pad in moisture conductive communication with the buffer receiving member, said conjugate pad comprising, a composition comprising a conjugate disposed in dry state, said conjugate comprising a colored particle and a first binder capable of binding the analyte; a membrane strip in moisture conductive communication with the conjugate pad, the membrane strip comprising a test area located downstream of the conjugate pad, the test area comprising a second binder agent immobilized therein for forming an immobilized complex with the analyte; a removable porous member for receiving the liquid sample, wherein said porous member is in contact with and located directly above the test area so as to cover the test area; and wherein the device is configured to provide a flowpath along which the buffer solution flows into the conjugate pad to mobilize the conjugates and form a mixture comprising the buffer and the mobilized conjugates, and along which flowpath the mixture flows into the membrane strip to the test area, wherein the buffer solution of the mixture washes the immobilized complexes in the test area.