Micro total analysis systems : proceedings of the ... [Mu] TAS International Conference on Miniaturized Chemical and Biochemical Analysis Systems. [Mu] TAS (Conference)最新文献

In this work, we demonstrate the differentiation of demodulated multifrequency signals from impedance sensitive microparticles when targeting surface receptors on neutrophils in a microfluidic impedance cytometer. These scheme uses a single signal input and detection configuration, and machine learning can differentiate particle types with up to 82% accuracy.

Small water microdroplets in microfluidic systems have a high surface charge density resulting from charged surfactants. As a result, an electric double layer forms inside the droplet. Depletion of ions from the center of the droplet to form the double layer can shift the concentration of ions dramatically from that of the microdroplet precursor solution. Here we show numerical solutions to the Gouy-Chapman model in spherical coordinates. Some notable effects include: 1) large percentages of the microdroplet volume experience very large DC electric fields; 2) many ions get forced into a Stern layer giving dramatically different conditions from the bulk.

In metastatic cancer, the secondary microenvironment consists of numerous cell types, each signaling with, and potentially supporting, the disseminated tumor cell. However, in vitro models have thus far been limited in their complexity, ultimately hindering study. To overcome this, we report the optimization and application of a high-throughput method, DNA-directed patterning, to pattern different cell types from the bone marrow microenvironment for the study of prostate cancer proliferation within this environment. We show that cells in our patterned microenvironment maintain their phenotype and behavior. Moreover, we demonstrate the successful introduction of prostate cancer cells in our microenvironment to investigate dormancy.

Circulating tumor cells (CTCs) are promising markers to determine cancer patient prognosis and track disease response to therapy. We present a multi-stage microfluidic device we have developed that utilizes inertial and Dean drag forces for isolating CTCs from whole blood. We demonstrate a 94.2% ± 2.1% recovery of cancer cells with our device when screening whole blood spiked with MCF-7 GFP cells.

We propose a method to separate photosystem I crystals based on size using a combination of dielectrophoresis (DEP) and electrokinesis (EK) within a microfluidic device. In this work, a model system utilizing polystyrene beads of two sizes is employed to observe the effects of DEP and EK on particles as they pass through a microsorter via electroosmosis. Particle counting and fluorescence intensity measurements are used for quantitative analysis of experimental data. For comparison, numerical simulations were performed for further confirmation that the proposed device is capable of sorting particles based on their size. Our experimental and theoretical results are in agreement and show a high degree of sorting efficiency between both particle types making this a promising solution for protein crystal sorting.

We report the construction and testing of a combinatorial multicomponent plug mixer (CMPM) chip that generates a large number of mix ratios. The CMPM chip has been designed to study ribonucleotide reductase (RNR) protein-protein/protein-ligand interaction networks. The 4-component chip is capable of 5400 different combinations in a 30 plug cycle. CMPM chips were tested producing fluorescent dye and dihydrofolate reductase NADPH/MX mixtures with plug lengths of 2 mm.

Currently, most of the integrated sorting modules in the microfabricated DEP-based and fluorescent-activated cell sorters (μFACS) still suffer from low-throughput operation and require complex fabrication process (e.g. embedded electrodes) and high power consumption (e.g. electrokinetically-driven sorters). In this paper, we demonstrate an easy-to-fabricate, low-powered and high-speed sorting module (at a single cell level) using an on-chip integrated piezoelectric (PZT) actuator. By controlling the bending motion of the PZT actuator, we have investigated and verified the high-speed flow-switching and sorting capabilities both theoretically (dynamic simulation) and experimentally using beads and biological agents.

We report a simplified flow cytometer design that makes use of negative dielectrophoresis (DEP) for particle focusing and integrated optical and AC impedance detectors to enable an inexpensive, compact and robust system for cell and particle characterization. This straightforward, modular design could be applied as a standalone instrument or as a particle detector in an integrated micro total analysis system.

We present the concept of a general-purpose sample analysis platform (GSAP) based on dielectrophoretic methods. The platform architecture comprises integrated functional blocks that can be programmed to perform a diverse range of analysis steps, including the on-device preparation of real world samples.