Immunosensor devices are usually manufactured in the form of a test strip and use the specific interaction of target protein and antibodies to elicit a color deposition when the two interact. The devices operate on the principal of lateral flow immunochromatography in which the various background components are separated across an absorbent membrane into discrete regions. These devices allow for rapid presumptive identification of both biological organisms and toxins in 15 minutes or less and require minimal training. No sample preparation is required. Results may be read visually, although strip reading devices can be used to improve consistency of analysis. The devices are disposable, contain no moving parts, have a long shelf life, and operate in a wide range of temperatures. There are well-validated devices for numerous BW targets. Unlike nucleic acid based detection devices, the immunoassays have the ability to directly detect toxins. A disadvantage is that the devices are typically not as sensitive as molecular based detection devices, and they only provide qualitative, not quantitative data.