Focusing of mammalian cells under an ultrahigh pH gradient created by unidirectional electropulsation in a confined microchamber†Electronic supplementary information (ESI) available: Figures S1-S5 and videos S1-S2. See DOI: 10.1039/c4sc00319eClick here for additional data file.Click here for additional data file.Click here for additional data file.

The transport and manipulation of cells in microfluidic structures are often critically required in cellular analysis. Cells typically make consistent movement in a dc electric field in a single direction, due to their electrophoretic mobility or electroosmotic flow or the combination of the two. Here we demonstrate that mammalian cells focus to the middle of a closed microfluidic chamber under the application of unidirectional direct current pulses.

Electroporation-based delivery of cell-penetrating peptide conjugates of peptide nucleic acids for antisense inhibition of intracellular bacteria.

Cell penetrating peptides (CPPs) have been used for a myriad of cellular delivery applications and were recently explored for delivery of antisense agents such as peptide nucleic acids (PNAs) for bacterial inhibition. Although these molecular systems (i.e.

Diffusion-based microfluidic PCR for "one-pot" analysis of cells.

Genetic analysis starting with cell samples often requires multi-step processing including cell lysis, DNA isolation/purification, and polymerase chain reaction (PCR) based assays. When conducted on a microfluidic platform, the compatibility among various steps often demands a complicated procedure and a complex device structure. Here we present a microfluidic device that permits a "one-pot" strategy for multi-step PCR analysis starting from cells.

Thermal loading in flow-through electroporation microfluidic devices.

Thermal loading effects in flow-through electroporation microfluidic devices have been systematically investigated by using dye-based ratiometric luminescence thermometry. Fluorescence measurements have revealed the crucial role played by both the applied electric field and flow rate on the induced temperature increments at the electroporation sections of the devices. It has been found that Joule heating could raise the intra-channel temperature up to cytotoxic levels (>45 °C) only when conditions of low flow rates and high applied voltages are applied.

Characterizing osmotic lysis kinetics under microfluidic hydrodynamic focusing for erythrocyte fragility studies.

The biomechanics of erythrocytes, determined by the membrane integrity and cytoskeletal structure, provides critical information on diseases such as diabetes mellitus, myocardial infarction, hypertension, and sickle cell anemia. Here we demonstrate a simple microfluidic tool for examining erythrocyte fragility based on characterizing osmotic lysis kinetics. Hydrodynamic focusing is used for generating rapid dilution of the buffer and producing lysis of erythrocytes during their flow.