| abstract |
Abstract A diagnostic test device is provided including a plate having at least one well, preferably a plurality of wells, each with an open bottom across which a composite membrane comprising three layers is placed, with a hydrophobic, liquid-tight seal provided at the periphery of each well. The composite membrane from the top or upstream side to the bottom or downstream side, in sequence, includes a first reaction or filtration layer formed from a thin, liquophilic, microporous membrane, a second or sealing layer, preferably a hydrophobic material in sheet or fiber form, such as nonwoven polypropylene fibers, and a liquophobic, preferably hydrophobic, barrier layer having one or more apertures which allows liquid to exit the well while eliminating lateral migration of a pendant liquid drop. The liquophobic seal provided by the liquophobic sealing layer eliminates "cross-talk" by lateral diffusion or wicking. |