Droplet-Based Microfluidics Methods for Detecting Enzyme Inhibitors.

Sub-nanoliter droplets produced in microfluidic devices have gained enormous importance for performing all kinds of biochemical assays. One of the main reasons is that the amounts of reagents employed can be reduced by approximately five orders of magnitude compared with conventional microplate assays. This chapter describes how to design, fabricate, and operate a microfluidic device to perform enzyme kinetics and enzyme inhibition assays in droplets. This procedure can be used effectively to screen a small library of compounds. Then, we describe how to use this droplet microfluidic setup to screen for potential inhibitor compounds eluted from a coupled high-performance liquid chromatography (HPLC) system that separates crude natural extracts.