Analytical isotachophoresis of lactate in human serum using dry film photoresist microfluidic chips compatible with a commercially available field-deployable instrument platform.

A dry film resist (DFR) chip compatible with the Agilent Bioanalyzer 2100 was designed and fabricated for use in the analysis of lactate in serum by chip isotachophoresis (ITP). The Agilent Bioanalyzer 2100 is a commercially available field deployable analytical instrument originally developed for the electrophoretic analysis of DNA, RNA and proteins. The DFR chip was designed for the ITP separation of lactate in human serum within 1 min and was made compatible with the Bioanalyzer after packaging in the plastic caddies normally used for the DNA chips.

Exploring chip-capillary electrophoresis-laser-induced fluorescence field-deployable platform flexibility: separations of fluorescent dyes by chip-based non-aqueous capillary electrophoresis.

Microfluidic chip electrophoresis (chip-CE) is a separation method that is compatible with portable and on-site analysis, however, only few commercial chip-CE systems with laser-induced fluorescence (LIF) and light emitting diode (LED) fluorescence detection are available. They are established for several application tailored methods limited to specific biopolymers (DNA, RNA and proteins), and correspondingly the range of their applications has been limited. In this work we address the lack of commercially available research-type flexible chip-CE platforms by exploring the limits of using an application-tailored system equipped with chips and methods designed for DNA separations as a generic chip-CE platform - this is a very significant issue that has not been widely studied.

Potential of capillary electrophoresis (CE) and chip-CE with dual detection (capacitively-coupled contactless conductivity detection (C4D) and fluorescence detection) for monitoring of nicotine and cotinine derivatization.

Capillary electrophoresis (CE) coupled with capacitively-coupled contactless conductivity (C(4)D) and fluorescence (FD) detectors and chip-CE for monitoring of nicotine and cotinine derivatization was demonstrated. Separation of the substrates and intermediates could be achieved by CE-C(4)D in 7 min (R(s) > 2.7) using 45 mM acetic acid (pH 3.

Separation of carboxylic acids in human serum by isotachophoresis using a commercial field-deployable analytical platform combined with in-house glass microfluidic chips.

Portable and field deployable analytical instruments are attractive in many fields including medical diagnostics, where point of care and on-site diagnostics systems capable of providing rapid quantitative results have the potential to vastly improve the productivity and the quality of medical care. Isotachophoresis (ITP) is a well known electrophoretic separation technique previously demonstrated as suitable for miniaturization in microfluidic chip format (chip-ITP). In this work, a purpose-designed ITP chip compatible with a commercial end-used targeted microfluidic system was used to study different injection protocols and to evaluate the effect of the length of the separation channel on the analytical performance.

Isotachophoresis on a chip with indirect fluorescence detection as a field deployable system for analysis of carboxylic acids.

ITP with indirect fluorescence detection (IFD) was introduced three decades ago. Despite this fact, the method has never become widely adopted. The main aim of this work was to utilize the ITP-IFD for the separation of carboxylic acids by using a commercially available, portable, microfluidic chip electrophoresis system.

Rapid separations of nile blue stained microorganisms as cationic charged species by chip-CE with LIF.

Rapid detection of microorganisms by alternative methods is desirable. Electromigration separation methods have the capability to separate microorganisms according to their charge and size and laser-induced fluorescence (LIF) detection have single-cell detection capability. In this work, a new combined separation and detection scheme was introduced using chip-based capillary electrophoresis (chip-CE) platform with LIF detection.

Chip-based CE for rapid separation of 8-aminopyrene-1,3,6-trisulfonic acid (APTS) derivatized glycans.

Fluorescently labeled carbohydrates released from glycoproteins were separated using a commercially available microfluidic chip electrophoresis system. While the instrumentation was primarily designed for DNA analysis it was found that the application base can be easily expanded using the development software provided by the manufacturer. The carbohydrates were released by enzymatic digestion (PNGase F) from glycoproteins present in human plasma after boronic acid - lectin affinity enrichment.

Prediction and understanding system peaks in capillary zone electrophoresis.

Introduction of a sample into the separation column (microchip channel) in capillary zone electrophoresis (microchip electrophoresis) will cause a disturbance in the originally uniform composition of the background electrolyte. The disturbance, a system zone, can move in some electrolyte systems along the separation channel and, on reaching the position of the detector, cause a system peak. As shown by the linear theory of electromigration based on linearized continuity equations formulated in matrix form, the mobility of the system zone--the system eigenmobility--can be obtained as the eigenvalue of the matrix.