Variable volume assay device and method.

摘要

An assay device for the detection of one or more components in a liquid sample, specifically antigens or antibodies in a biologically derived sample. The device defines a chamber (12) of variable volume which is essentially sealed except for a membrane (24) across an inlet port. The sample is placed on the exterior of the membrane (24). It is drawn to the chamber by suction created by decreasing the volume of the chamber (12). Liquid within the chamber (12) is forced out of it under internal pressure created by decreasing the chamber volume. The chamber volume can be varied by twisting of a threadedly mounted piston (16) in a body. In one embodiment, a sandwich assay for the detection of an antigen in a sample, the antigen is bound to immobilized antibody on a distinct region of the membrane and is also reacted with labeled antibody for detection. The sample is cycled through the membrane by varying the chamber volume.