Extracellular vesicles (EVs) including exosomes and microvesicles have attracted considerable attention in the fields of cell biology and medicine. For a better understanding of EVs and further exploration of their applications, the development of analytical methods for biological nanovesicles has been required. In particular, considering the heterogeneity of EVs, methods capable of measuring i...

In this paper, we are evaluating the strategy of sorting peptides/proteins based on the charge to mass without resorting to ampholytes and/or isoelectric focusing, using a single- and two-step free-flow zone electrophoresis. We developed a simple fabrication method to create a salt bridge for free-flow zone electrophoresis in PDMS chips by surface printing a hydrophobic layer on a glass substra...

Assessing microbiological quality assurance by monitoring bacteria in various sources of freshwater used for human consumption, recreation, and food preparation is important for a healthy life. Bacterial number and their community structure in freshwater should be determined as quickly as possible, and "real-time" and "on-site" microbiological methods are required. In this study, we examined th...

In this paper, a rapid and simple method to determine the optimal temperature conditions for denaturant electrophoresis using a temperature-controlled on-chip capillary electrophoresis (CE) device is presented. Since on-chip CE operations including sample loading, injection and separation are carried out just by switching the electric field, we can repeat consecutive run-to-run CE operations on...

Microsatellite instability (MSI) is caused by a failure of the DNA mismatch repair system and occurs frequently in various types of cancer. Since sporadic MSI are associated with approximately 10 to 15% of colorectal, gastric or endometrial carcinoma and impact clinical prognosis, MSI analysis is an important tool in clinical research and molecular diagnostics. Given that conventional technique...

On-column conductivity detection in capillary-chip electrophoresis was achieved by actively coupling the high electric field with two sensing electrodes connected to the main capillary channel through two side detection channels. The principle of this concept was demonstrated by using a glass chip with a separation channel incorporating two double-Ts. One double-T was used for sample introducti...

We present a systematic, experimentally validated method of designing electrokinetic injections for on-chip capillary electrophoresis applications. This method can be used to predict point-wise and charge-coupled device (CCD)-imaged electropherograms using estimates of species mobilities, diffusivities and initial sample plug parameters. A simple Taylor dispersion model is used to characterize ...

A capacitively coupled contactless conductivity detector produced in Low Temperature Co-fired Ceramic (LTCC) technology for microchip capillary electrophoresis (CE) is reported in this work. Electrodes located outside the measurement channel are used to sense impedance variations caused by conductive ions. The application of LTCC in combination with contactless conductivity detection is very pr...

A monolithic capillary electrophoresis system with integrated on-chip fluorescence detection has been microfabricated on a silicon substrate. Photodiodes in the silicon substrate measure fluorescence emitted from eluting molecules. An on-chip thin film interference filter prevents excitation light from inhibiting the fluorescence detection. A transparent conducting ground plane prevents the hig...

Electrophoretic separation techniques using microchips have been dramatically improved and several commercial MCE systems have been developed. For example, the Agilent Technologies 2100 Bioanalyzer system is commercially available with a protein separation chip and reagent kit that enables rapid and highly efficient protein separation based on their molecular size [1]. Separation of protein mix...