Droplet microfluidics for high-throughput biological assays

Abstract

Droplet microfluidics offers significant advantages for performing high-throughput screens and sensitive assays. Droplets allow sample volumes to be significantly reduced, leading to concomitant reductions in cost. Manipulation and measurement at kilohertz speeds enable up to 10(8) samples to be screened in one day. Compartmentalization in droplets increases assay sensitivity by increasing the effective concentration of rare species and decreasing the time required to reach detection thresholds. Droplet microfluidics combines these powerful features to enable currently inaccessible high-throughput screening applications, including single-cell and single-molecule assays.

Resuscitation of Pseudomonas aeruginosa from dormancy requires hibernation promoting factor (PA4463) for ribosome preservation

“…The colony size and variable rRNA levels of the starved Δhpf mutant cells suggested that there was heterogeneity in the resuscitating population. Therefore, we used a drop-based microfluidic approach (34) to quantify the heterogeneity in this population. These drop-based experiments allowed us to differentiate and quantify individual cells undergoing resuscitation from the nondividing cells within many drop-based bioreactors.…”

Surfactant adsorption kinetics in microfluidics

“…The compounds are used widely for the stabilization of foams and emulsions for food and cosmetic products, painting materials, and industrial coatings (3). Emulsions are nowadays also used in combination with microfluidic systems for applications in biotechnology (3)(4)(5)(6)(7)(8)(9)(10)(11). An emulsion is a dispersion of one liquid phase into another, stabilized by surfactants in a metastable state.…”

“…The kinetic stabilization of emulsions occurs through several mechanisms, involving electrostatic or steric repulsion and the buildup of Marangoni stresses to improve the lifetime of emulsions against coalescence (12, 13). On the other hand, surfactants are involved in transport processes such as Ostwald ripening or solute transport, which mediates the chemical equilibration of the system (14-17): in general, all processes affecting the lifetime of emulsions (coalescence, rupture, exchange, and loss of molecules) are directly related to the physics and dynamics of the surfactant molecules at interfaces (3,4,6,10,11,15,16). The first analysis of surfactant layers dates back to the 18th century with Franklin's experiments (1) and the first comprehensive studies on adsorption kinetics by Ward and Tordai (18) and Langmuir (19).…”

A label-free microfluidic assay to quantitatively study antibiotic diffusion through lipid membranes

“…The small sample amounts required, high throughput capabilities and controlled microenvironments involved offer many advantages for the development of drug assays 5,6,7,8,9,10 . In this work, we develop a novel microfluidic technique to quantitatively examine the passive diffusion of antibiotics across lipid membranes.…”