EchoTilt: An Acoustofluidic Method for the Capture and Enrichment of Nanoplastics Directed Toward Drinking Water Monitoring.

Micro- and nanoplastics have become increasingly relevant as contaminants to be monitored due to their potential health effects and environmental impact. Nanoplastics, in particular, have been shown to be difficult to detect in drinking water, requiring new capture technologies. In this work, we applied the acoustofluidic seed particle method to capture nanoplastics in an optimized, tilted grid of silica clusters even at the high flow rate of 5 mL/min.

EchoGrid: High-Throughput Acoustic Trapping for Enrichment of Environmental Microplastics.

The health hazards of micro- and nanoplastic contaminants in drinking water has recently emerged as an area of concern to policy makers and industry. Plastic contaminants range in size from micro- (5 mm to 1 μm) to nanoplastics (<1 μm). Microfluidics provides many tools for particle manipulation at the microscale, particularly in diagnostics and biomedicine, but has in general a limited capacity to process large volumes.

High-throughput cell spheroid production and assembly analysis by microfluidics and deep learning.

3D cell culture models are important tools in translational research but have been out of reach for high-throughput screening due to complexity, requirement of large cell numbers and inadequate standardization. Microfluidics and culture model miniaturization technologies could overcome these challenges. Here, we present a high-throughput workflow to produce and characterize the formation of miniaturized spheroids using deep learning.

A Portable, Negative-Pressure Actuated, Dynamically Tunable Microfluidic Droplet Generator.

Droplet microfluidics utilize a monodisperse water-in-oil emulsion, with an expanding toolbox offering a wide variety of operations on a range of droplet sizes at high throughput. However, translation of these capabilities into applications for non-expert laboratories to fully harness the inherent potential of microscale manipulations is woefully trailing behind. One major obstacle is that droplet microfluidic setups often rely on custom fabricated devices, costly liquid actuators, and are not easily set up and operated by non-specialists.

Pooled CRISPRi screening of the cyanobacterium Synechocystis sp PCC 6803 for enhanced industrial phenotypes.

Cyanobacteria are model organisms for photosynthesis and are attractive for biotechnology applications. To aid investigation of genotype-phenotype relationships in cyanobacteria, we develop an inducible CRISPRi gene repression library in Synechocystis sp. PCC 6803, where we aim to target all genes for repression.

Rapid Production and Recovery of Cell Spheroids by Automated Droplet Microfluidics.

The future of the life sciences is linked to automation and microfluidics. As robots start working side by side with scientists, robotic automation of microfluidics in general, and droplet microfluidics in particular, will significantly extend and accelerate the life sciences. Here, we demonstrate the automation of droplet microfluidics using an inexpensive liquid-handling robot to produce human scaffold-free cell spheroids at high throughput.

RNAi expression tuning, microfluidic screening, and genome recombineering for improved protein production in .

The cellular machinery that supports protein synthesis and secretion lies at the foundation of cell factory-centered protein production. Due to the complexity of such cellular machinery, the challenge in generating a superior cell factory is to fully exploit the production potential by finding beneficial targets for optimized strains, which ideally could be used for improved secretion of other proteins. We focused on an approach in the yeast that allows for attenuation of gene expression, using RNAi combined with high-throughput microfluidic single-cell screening for cells with improved protein secretion.

Development of a Bacterial Biosensor for Rapid Screening of Yeast p-Coumaric Acid Production.

Transcription factor-based biosensors are used to identify producer strains, a critical bottleneck in cell factory engineering. Here, we address two challenges with this methodology: transplantation of heterologous transcriptional regulators into new hosts to generate functional biosensors and biosensing of the extracellular product concentration that accurately reflects the effective cell factory production capacity. We describe the effects of different translation initiation rates on the dynamic range of a p-coumaric acid biosensor based on the Bacillus subtilis transcriptional repressor PadR by varying its ribosomal binding site.

Multiple pathogen biomarker detection using an encoded bead array in droplet PCR.

We present a droplet PCR workflow for detection of multiple pathogen DNA biomarkers using fluorescent color-coded Luminex® beads. This strategy enables encoding of multiple singleplex droplet PCRs using a commercially available bead set of several hundred distinguishable fluorescence codes. This workflow provides scalability beyond the limited number offered by fluorescent detection probes such as TaqMan probes, commonly used in current multiplex droplet PCRs.

Picodroplet partitioned whole genome amplification of low biomass samples preserves genomic diversity for metagenomic analysis.

Background: Whole genome amplification (WGA) is a challenging, key step in metagenomic studies of samples containing minute amounts of DNA, such as samples from low biomass environments. It is well known that multiple displacement amplification (MDA), the most commonly used WGA method for microbial samples, skews the genomic representation in the sample. We have combined MDA with droplet microfluidics to perform the reaction in a homogeneous emulsion.

Integration of a Droplet-Based Microfluidic System and Silicon Nanoribbon FET Sensor.

We present a novel microfluidic system that integrates droplet microfluidics with a silicon nanoribbon field-effect transistor (SiNR FET), and utilize this integrated system to sense differences in pH. The device allows for selective droplet transfer to a continuous water phase, actuated by dielectrophoresis, and subsequent detection of the pH level in the retrieved droplets by SiNR FETs on an electrical sensor chip. The integrated microfluidic system demonstrates a label-free detection method for droplet microfluidics, presenting an alternative to optical fluorescence detection.

Single-cell screening of photosynthetic growth and lactate production by cyanobacteria.

Background: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible.

Results: We present a method for high-throughput, single-cell analysis and sorting of genetically engineered l-lactate-producing strains of Synechocystis sp.

Controlled Lateral Positioning of Microparticles Inside Droplets Using Acoustophoresis.

In this paper, we utilize bulk acoustic waves to control the position of microparticles inside droplets in two-phase microfluidic systems and demonstrate a method to enrich the microparticles. In droplet microfluidics, different unit operations are combined and integrated on-chip to miniaturize complex biochemical assays. We present a droplet unit operation capable of controlling the position of microparticles during a trident shaped droplet split.

Metabolite profiling of microfluidic cell culture conditions for droplet based screening.

We investigate the impact of droplet culture conditions on cell metabolic state by determining key metabolite concentrations in S. cerevisiae cultures in different microfluidic droplet culture formats. Control of culture conditions is critical for single cell/clone screening in droplets, such as directed evolution of yeast, as cell metabolic state directly affects production yields from cell factories.

Microfluidic screening and whole-genome sequencing identifies mutations associated with improved protein secretion by yeast.

There is an increasing demand for biotech-based production of recombinant proteins for use as pharmaceuticals in the food and feed industry and in industrial applications. Yeast Saccharomyces cerevisiae is among preferred cell factories for recombinant protein production, and there is increasing interest in improving its protein secretion capacity. Due to the complexity of the secretory machinery in eukaryotic cells, it is difficult to apply rational engineering for construction of improved strains.

Automated analysis of dynamic behavior of single cells in picoliter droplets.

We present a droplet-based microfluidic platform to automatically track and characterize the behavior of single cells over time. This high-throughput assay allows encapsulation of single cells in micro-droplets and traps intact droplets in arrays of miniature wells on a PDMS-glass chip. Automated time-lapse fluorescence imaging and image analysis of the incubated droplets on the chip allows the determination of the viability of individual cells over time.

High-throughput screening for industrial enzyme production hosts by droplet microfluidics.

A high-throughput method for single cell screening by microfluidic droplet sorting is applied to a whole-genome mutated yeast cell library yielding improved production hosts of secreted industrial enzymes. The sorting method is validated by enriching a yeast strain 14 times based on its α-amylase production, close to the theoretical maximum enrichment. Furthermore, a 10(5) member yeast cell library is screened yielding a clone with a more than 2-fold increase in α-amylase production.

Multiplex analysis of enzyme kinetics and inhibition by droplet microfluidics using picoinjectors.

Enzyme kinetics and inhibition is important for a wide range of disciplines including pharmacology, medicine and industrial bioprocess technology. We present a novel microdroplet-based device for extensive characterization of the reaction kinetics of enzyme substrate inhibitor systems in a single experiment utilizing an integrated droplet picoinjector for bioanalysis. This device enables the scanning of multiple fluorescently-barcoded inhibitor concentrations and substrate conditions in a single, highly time-resolved experiment yielding the Michaelis constant (Km), the turnover number (kcat) and the enzyme inhibitor dissociation constants (ki, ki').

Droplet microfluidics--a tool for single-cell analysis.

Droplet microfluidics allows the isolation of single cells and reagents in monodisperse picoliter liquid capsules and manipulations at a throughput of thousands of droplets per second. These qualities allow many of the challenges in single-cell analysis to be overcome. Monodispersity enables quantitative control of solute concentrations, while encapsulation in droplets provides an isolated compartment for the single cell and its immediate environment.