Abstract: Methods and kits are described for performing immunoassays. The kit includes a reaction cell having a microporous membrane and an absorbent capable of drawing liquid sample through the membrane. An applicator is provided for applying a small volume of the liquid sample to the membrane by contacting a port of the applicator to the membrane and allowing the sample to flow therethrough by capillary action. Analyte in the sample is immobilized, typically by immunoadsorption, and the immobilized analyte may then be visualized using conventional signal producing systems, such as color, fluorescence, and luminescent systems.