Functional Packaging of Lateral Flow Strip Allows Simple Delivery of Multiple Reagents for Multistep Assays.

This paper presents a rotary device designed for facile delivery of multiple reagents to a paper strip for multistep assays. Its purpose is to allow users to easily perform multistep assays and achieve sensitive detection. While the test strip remains stationary, rotating the top piece of the device aligns the reagent and absorbent pads to each end of the paper strip and initiates fluid flow. Further incremental rotation makes an adjacent pair of pads to align simultaneously, causing fluid flow of subsequent reagent that was preloaded in the reagent pad. In this work, various porous substrates were tested to observe their effect on overall flow rate of the system and multistep assays were performed to demonstrate its simple use. As a proof of concept, enzyme-linked immunosorbent assay was carried out to detect Escherichia coli O157:H7.