Microfluidic multiplexed device for amino acid quantification using cell-free protein synthesis

Abstract

Since amino acid analysis is crucial for monitoring and detecting metabolic states, rapid and easy methods are in high demand. Various metabolic diseases caused by the accumulation of specific amino acids due to abnormal metabolic pathways are fatal and can be diagnosed by measuring the level of amino acids in biological fluids. However, several techniques capable of performing amino acid analysis require complex experimental setup, expensive equipment, and long processing time. Here, we introduce a power-free, portable, and efficient microfluidic device for amino acid quantification using a cell-free system, which is essential for fast processing and direct manipulation. In this platform, the working principle of a finger-actuated pumping unit is applied, and multiple reactions are operated simultaneously with a single button. In addition to the complementary cell-free protein synthesis assay which was previously studied, the device reduces the amount of sample and allows a simple mixing process through a pushbutton. In addition, the reactants that have been reacted in the incubation chambers flow into a detection zone where results can be observed and compared at a glance. Through the platform, the amino acid concentrations can be determined simply by measuring fluorescence signals and also facilitate the diagnosis of amino acid-related diseases.