Abstract: An assay test device, suitable for use as a home pregnancy test kit, comprises a casing and two test panels mounted to an elongate arm. The test panels are held within the casing for storage. Manual operation of a slider causes the test panels to project outwardly from an end of the casing, so that a liquid test sample may be administered to the panels. The panels are then withdrawn into the casing, which has a window allowing the test panels to be observed while the test reaction (typically an ELISA test) takes place. Indicia may be applied to reveal messages when a test panel changes color. The casing and other components comprise a polyolefin treated to be oxo-biodegradable or biodegradable, so that they may rapidly break down in aerobic conditions on disposal.