LAUSR

Microfluidic systems are important for performing precise reagent manipulations and reducing material consumption in biological assays. However, optical detection methods limit analyses to fluorescent or UV-active compounds and traditional 2D fluidic designs have limited degrees of freedom. This article describes a microfluidic device that has three inputs and performs 2592 distinct enzyme reactions using only 150 μL of reagent with quantitative characterization. This article also introduces imaging self-assembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry (iSAMDI-MS) to map reaction progress, by immobilization of the product onto the floor of the microfluidic channel, into an image that is used for calculating the Michaelis constant ( Km). This approach expands the scope of imaging mass spectrometry, microfluidic detection strategies, and the design of high-throughput reaction systems.