Microfluidics for biology:
We develop microfluidic devices to very precisely control small drops of one fluid in a second carrier fluid. The volume of each drop is between about a picoliter and a nanoliter. We use each drop as a carrier or reaction vessel. We are able to very precisely control these reaction vessels and can mix, add, divide and sort these drops at rates of 1 to 100 kHz. This enables us to carry out very large numbers of reactions in short times with very small quantities of reagents. Many of the applications of this technology are for the study of biology, and we, therefore, typically use aqueous drops in an inert carrier oil. We use the drops to do ultra-high-throughput screening of different biomolecules. We also use the drops to encapsulate single cells, enabling us to do very high-throughput studies of populations of cells, all at the level of single cells. We are exploring a wide range of potential applications from fundamental studies of evolution to single cell selection to applications in drug discovery and diagnostics. Several of the concepts have led to the formation of start-up companies based on this technology.
Rapid evaluation of antibiotics: The aim of this project is to radically reduce the time needed to evaluate which antibiotics are most effective for a partcular infection. Jonathan Didier 
Droplet chemostats: A droplet system, which integrates the capabilities of mixing, nutrient addition, waste removal, and temperature control seemlessly, could provide an array of chemostats, each hosting an independent population of organisms. This would allow microbiologists to obtain good statistics on many populations of cells growing in well-regulated, steady-state conditions. Don Aubrecht, Nick Carroll, and Lloyd Ung
Single-cell PCR: The polymerase chain reaction (PCR) has wide-ranging applications, especially in medical diagnostics, and is therefore crucial for analyzing small amounts of molecules or cells that must be amplified to higher levels before downstream detection or sequencing steps. However, clinical samples such as blood from sepsis patients may carry pathogenic targets at concentrations as low as 1-10 microbes/mL, against a background of 10 million white blood cells/mL. Even if the white blood cells are somehow removed, the reaction will easily be contaminated by aerosols, dust, and other incidental sources of noise. One solution is to increase the signal-to-noise ratio by increasing the effective concentration of target molecules that constitute the signal. Droplet microfluidics uses this approach to enable single-template PCR. Mira Guo
Droplet-based technology for cell and nucleic acid analysis with potential clinical application. Yong Guo
Picoinjectors: High-throughput injection of microfluidic droplets. Tony Hung 
Microfluidic screening in drug discovery and development: Microfluidics allow one to overcome major limitations associated with the traditional screening technologies, while enabling screening of extensive sets of experimental conditions with sub-nanolitre volumes in a more controllable way. Therefore, this project aims to develop microfluidic platforms for (i) pharmaceutical cocrystals screening, (ii) drug cytotoxicity screens, and (iii) formulation screening at the early stage of development. Sabiruddin Mirza 
Droplet-based isothermal DNA amplification: PCR is a sensitive method for detection of changes in DNA sequence. Isothermal amplification takes advantage of the amplification inherent to PCR, but can be done without thermal cycling and results in a sensitive method easily integrated in a droplet microfluidic device. Lianfeng Shan 
DNA sequencing in microfluidic droplets: Currently I am working on DNA sequencing in microfluidic droplets together with my colleagues Pascaline Mary, Tony Hung and Adam Abate. Related side projects include parallel encapsulation of samples to generate large droplet libraries and fluorescent barcode labels to identify droplets. Ralph Sperling 
Development of a High-Throughput Droplet Sorting Instrument A droplet microfluidic system for screening and sorting single droplets, according to their fluorescence, is the basis of a number of the biological assays being developed in the Weitz Lab. This technology has enormous potential for research in biology ranging from studying the genome of a single bacterial cell to understanding the evolution of viral diversity. Lloyd Ung 
Encapsulation of single cells into alginate microgels: The application of droplet-based microfluidics in single cell assays provides a powerful tool for highly sensitive biological analysis. The small sample amount also allows for a significant reduction of costs and time. Nevertheless, several applications require long term cell culturing which cannot be performed in aqueous drops since the necessary exchange of cell culture medium is difficult. A powerful way to solve this problem and increase the potential of droplet-based microfluidics is the encapsulation of single cells into hydrogels such as alginate that can easily be transferred into aqueous environments without losing the integrity of the microenvironment. In water, a permanent exchange of the cell surrounding culture medium becomes possible while the cells are trapped in their hydrogel niches. Stefanie Utech 
Single cell-based microfluidic device as a diagnostic tool for high-throughput drug screening: Finding a sufficient drug combination that allows for the most efficient treatment of diseases like cancer is still a challenging task which is further complicated by the patient's specific response. To simplify this procedure, we are working on the design of a high-throughput analytic tool for the evaluation of drug and drug mixtures effectiveness. Via encapsulation of single cells into picoliter droplets, we are able to efficiently scan large numbers of samples using minimal amounts of precious materials, e.g., patient primary cells. Via picoinjection precisely controlled amount of drugs can be injected into the droplets. Afterwards the drops can be analyzed to evaluate the efficiency of the injected drug. Therefore, we hope to be able to find the most efficient patient-specific drug combination and hence, allow for a more efficient cancer treatment. Stefanie Utech 
Mosquito millifluidics: We are currently developing millifluidic devices, which use well-defined fluid flows to dissect mosquitoes. Jim Wilking 
Droplet-based digital PCR: Digital PCR uses partitioning to provide a digital readout of the number of DNA strands present in a sample. Here, digital PCR is performed in droplets to increase sensitivity and reduce reagent use. In particular, the droplet digital PCR technique will be applied to studying low abundance gene mutations. Huidan Zhang 
Droplet-based single cell and single molecule screens: Micro sized aqueous droplets are ideal containers, which enable fundamental biological studies on both the single cell and single molecule level, and high-throughput screening on a target of interest. I am working on both aspects, in three projects. Yizhe Zhang