Agglutination reaction device having geometrically modified chambers

Abstract

A device for performing agglutination immunoassay reactions and the like is disclosed. The device includes a first hydrophilic layer, a second liquid-occlusive layer parallel to and overlying the first layer, and a third layer parallel to and overlying the second layer. The third layer has a transparent opening for observing particles. The second layer is interposed between and in adherent relationship to the first and third layers. The second layer has at least one slot defining a channel for directing liquid conducted by capillary action through the chamber defined in conjunction with the first and third layers. This chamber has a proximate zone and a distal zone. The geometry of the chamber is modified to provide preferably outwardly diverging walls and provide a flowpath having different rates of flow per unit area along the paths. This arrangement of different paths in the chamber allows agglutination reactions in the chamber to result in the formation of a non-random pattern of aggregated particles in the distal zone of the chamber. Such a non-random pattern is more readily observable than a random pattern of aggregated particles.