| abstract |
A multilayer test strip includes a first layer having an indicator reagent within a porous substrate, a second layer, overlying the first layer, including a reactive reagent, and a third layer, overlying the second layer, including a spreading agent that promotes the spreading of a liquid upon the third layer. Alternatively, the spreading agent may be mixed into the second layer. An inert backing with an aperture therethrough is positioned over these layers, with the substrate remote from the cover layer. |