A chemical analysis test device for detection of a selected chemical in a biological fluid is disclosed wherein the test is preformed on a rigid base containing a detection well for holding a reagent and a specimen well for holding a sample of the biological fluid to be tested. The detection well is positioned above a concentration chamber wherein the cross-sectional area of the chamber increases as the distance from the bottom of the detection well increases. A passage connects the concentration chamber to the detection well. The specimen well has a generally hemispherical interior surface and has an opening in the bottom thereof. A strip of wicking material is secured to the base interconnecting the opening in the specimen well and the concentration chamber. A specimen of the biological fluid to be tested is deposited in the specimen well and contacts the wicking material through the opening in the bottom of the well. The wicking paper wicks the specimen across to the concentration chamber and is treated with an agent to volatilize the chemical under test. The volatilized chemical is concentrated by the concentration chamber and forced through the passage into contact with the reagent stored in the detection well, producing a visible color change in the detection well above the passage, indicative of the chemical content in the biological fluid.

A self-contained assay device is provided, where an analyte may be detected or be quantitated by measuring the distance of a detectable signal from a predetermined site. The device employs two strips separated by a gap, where a flow path is completed by movement of a sample receiving pad into the gap. The movement of the sample receiving pad also results in release of a reagent solution which is then transported through the pad into the quantitation area where the amount of analyte may be determined. Various chemistries may be employed for providing a detectable signal. r

Test carrier for analyzing a sample fluid with several test layers which form a sample fluid transport path and contain a reagent system which reacts with the sample fluid to produce a detectable signal. The test carrier includes a reservoir layer of absorbent material, a detection layer arranged in the fluid transport path downstream the reservoir layer, in which a detectable signal is formed, and a separating layer arranged between the reservoir layer and the detection layer. The separating layer makes a two-step process possible. Fluid contact between the reservoir layer and the detection layer arises only with pressure loading of the layer assembly of the reservoir layer, separating layer and detection layer. A more uniform optical detection signal, and consequently better accuracy, can be achieved because the separating layer is made up of a hydrophilic material, wich is in the form of a lattice-shaped structure, in which the mean width of the lattice openings is more than 0.05 mm, and the threads from which the lattice-shaped structure is formed are multi-filament.

On a carrier layer there are arranged several test layers which are at least partly in fluid contact with one another, enabling liquid exchange. On the carrier layer are arranged an application zone, a detection zone for the production of a detectable signal characteristic of the analytical determination, which contains at least one said test layer which is a reaction layer, and an absorption zone with a test layer which is an absorptive layer of an absorbent material, wherein the reaction layer and absorption zone are positioned next to each other. Between the application and the absorption zone is a capillary-active transport path on the carrier layer which connects the application zone and the absorption zone. The reaction layer is arranged parallel to the transport path between the application zone and the absorption zone in such a manner that it is in liquid contact with a liquid transported in the transport path. The absorption zone therefore absorbs excess liquid and permits dosing the reaction layer with a reproducible amount of sample.