Patent ID: 8343726

Claim:
A method of detecting at least one substance of interest in a liquid sample, said method comprising: providing a liquid sample comprising or suspected of comprising the substance(s) of interest; applying the liquid sample to at least partially wet a porous material, wherein the porous material physically contacts a porous membrane comprising at least one specific binding pair member that is capable of binding, either directly or indirectly, the substance(s) of interest, and wherein the porous material is in physical contact with a bottom side of the porous membrane to allow for continuous diffusion and interaction of at least a portion of the sample and the specific binding pair member(s), and where the specific binding pair member(s) are in continuous contact with the porous material to allow for continuous diffusion of the sample between the porous material and the specific binding pair member(s), which are located directly above the porous material to which the liquid sample was applied; maintaining the porous material and porous membrane in contact for a sufficient amount of time for liquid present in the porous material to diffuse upwards into the porous membrane comprising the specific binding pair member(s), wherein diffusion of the liquid into the porous membrane results in the substance(s) of interest, if present, to be bound, either directly or indirectly, to the specific binding pair member(s); and detecting the presence or absence of a complex comprising the specific binding pair member(s) and the substance(s) of interest, wherein the presence of at least one complex indicates the presence of at least one of the substances of interest in the liquid sample.