Abstract: This invention relates to a method for establishing and using a decision marker by which positive samples can be discriminated from negative samples. The method employs the analysis of multiple samples from confirmed positive and negative samples. A fluorescence channel is selected so that the desired sensitivity and specificity are achieved. A microparticle having this fluorescence channel then is made and is used in conjunction with a fluorescence marker which is specific for the population of interest.

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.