On-Demand Droplet Collection for Capturing Single Cells.

Droplet-based microfluidic techniques are extensively used in efficient manipulation and genome-wide analysis of individual cells, probing the heterogeneity among populations of individuals. However, the extraction and isolation of single cells from individual droplets remains difficult due to the inevitable sample loss during processing. Herein, an automated system for accurate collection of defined numbers of droplets containing single cells is presented.

Sialyl Lewis-P-selectin cascade mediates tumor-mesothelial adhesion in ascitic fluid shear flow.

Organ-specific colonization suggests that specific cell-cell recognition is essential. Yet, very little is known about this particular interaction. Moreover, tumor cell lodgement requires binding under shear stress, but not static, conditions.

Picoinjection-Enabled Multitarget Loop-Mediated Isothermal Amplification for Detection of Foodborne Pathogens.

In this study, we develop a method to detect multiple DNAs of foodborne pathogens by encapsulating emulsion droplets for loop-mediated isothermal amplification (LAMP). In contrast to the traditional bulk-phase LAMP, which involves a labor-intensive mixing process, with our method, different primers are automatically mixed with DNA samples and LAMP buffers after picoinjection. By directly observing and analyzing the fluorescence intensity of the resultant droplets, one can detect DNA from different pathogens, with a detection limit 500 times lower than that obtained by bulk-phase LAMP.

Modeling Ovarian Cancer Multicellular Spheroid Behavior in a Dynamic 3D Peritoneal Microdevice.

Ovarian cancer is characterized by extensive peritoneal metastasis, with tumor spheres commonly found in the malignant ascites. This is associated with poor clinical outcomes and currently lacks effective treatment. Both the three-dimensional (3D) environment and the dynamic mechanical forces are very important factors in this metastatic cascade.

One-step immunoassay of C-reactive protein using droplet microfluidics.

We present a wash-free high-sensitivity immunoassay of C-reactive proteins with droplet microfluidics. Microbeads are encapsulated within droplets for the immunoassay, and the droplets are scanned by a fluorescence detection platform to quantify the amount of proteins captured on the microbeads. The limit of detection determined by our platform is 0.

Stemness and chemoresistance in epithelial ovarian carcinoma cells under shear stress.

One of greatest challenges to the successful treatment of cancer is drug resistance. An exciting approach is the eradication of cancer stem cells (CSCs). However, little is known about key signals regulating the formation and expansion of CSCs.

Asymmetric-detection time-stretch optical microscopy (ATOM) for ultrafast high-contrast cellular imaging in flow.

Accelerating imaging speed in optical microscopy is often realized at the expense of image contrast, image resolution, and detection sensitivity--a common predicament for advancing high-speed and high-throughput cellular imaging. We here demonstrate a new imaging approach, called asymmetric-detection time-stretch optical microscopy (ATOM), which can deliver ultrafast label-free high-contrast flow imaging with well delineated cellular morphological resolution and in-line optical image amplification to overcome the compromised imaging sensitivity at high speed. We show that ATOM can separately reveal the enhanced phase-gradient and absorption contrast in microfluidic live-cell imaging at a flow speed as high as ~10 m/s, corresponding to an imaging throughput of ~100,000 cells/sec.