Optimization of a Droplet-Based Millifluidic Device to Investigate the Phase Behavior of Biopolymers, Including Viscous Conditions

Abstract

Phase diagrams are widely used to map and control the assembly states of biopolymers. However, these studies are highly time and material consuming. Here, we present the optimization of a simple tool based on millifluidics to screen phase diagram of biopolymers, pure or in mixtures with other biopolymers. It is used (i) to generate a homogeneous mixture of biopolymers/buffer and/or biopolymers 1/ biopolymers 2 in a short time (~s), (ii) to vary the composition of the mixtures by adjusting the flow rates, and (iii) to determine the turbidity of the drop by grey level analysis. The mixing efficiency and the calibration turbidity vs. grey level were performed using colloidal titanium dioxide dispersions. The use of millifluidics reduced the amount of material of ten-fold and the experimentation time by a factor five compared to a conventional bulk approach. This set-up was used to explore functional synergies between proteins and polysaccharides as an example of application.