Macrofluidic Device for Preparative Concentration Based on Epitachophoresis

Abstract

We have developed a new separation device to concentrate and collect ions from several milliliter sample volumes to microliter fractions. Unlike most conventional platforms, this device has circular architecture. The electrophoretic migration operates from the outer perimeter toward the center. Separations can be performed both in continuous (zone electrophoresis) and discontinuous (moving boundary) electrolyte systems. We use a discontinuous electrolyte system comprising a leading and a terminating electrolyte to concentrate samples containing small organic anions and DNA fragment. The agarose gel stabilizes the boundary between the leading and terminating electrolytes. The milliliter volume sample is mixed with the terminating electrolyte and migrates through the gel toward the center. The concentrated total sample is collected in microliter fraction at the center. The potential for preparative concentration of DNA is demonstrated using a DNA ladder. Because zone migration accelerates as it moves toward the center, we named this method Epitachophoresis from the Greek word "επιταχυνω (epitachyńο)", meaning "acceleration". To the best of our knowledge, this unique circular architecture has not been previously described.

Practical sample pretreatment techniques coupled with capillary electrophoresis for real samples in complex matrices

“…Later developments involve the use of microfluidic devices, as pioneered by Santiago et al [90]. Thus, ITP is a promising sample pretreatment technique for nucleic acids providing lower losses of trace analytes and EFs of several orders of magnitude [91,92,93,94], in contrast to current techniques such as SPE. Applications include DNA purification, extraction, fractionation, and extraction from single cells and/or hybridization.…”

A simple micropreparative gel electrophoresis technique for purification of proteins, nucleic acids, and bioconjugates

“…The separation and purification of biological macromolecules are crucial not only for bioanalytics but also for advancements in biotechnology [1]. Macromolecules, in particular proteins and nucleic acids, can be isolated using a slew of techniques including high-speed centrifugation, membrane-based ultrafiltration, precipitation, electrophoresis, and chromatography [2][3][4][5][6][7]. These techniques differ in aspects such as scalability, throughput, yield, purity, precision, laboratory accessibility, and procedural complexity.…”

“…While flow chromatography systems especially benefit from relatively high throughput and scalability [5,8,9], several analytical applications such as sequencing and protein crystallography require only a small amount of purified protein. For such applications, techniques such as polyacrylamide gel electrophoresis (PAGE) are used to separate biomolecules according to their size and net electric charge [10,11].…”

Purification of anionic fluorescent probes through precise fraction collection with a two‐point detection system using multiple‐stacking preparative capillary transient isotachophoresis

“…Foret et al developed epitachophoresis for concentration and collection. This method succeeded in increasing the sample injection volume up to several milliliters with gel electrophoresis using a circular electrode [22]. The multiple injection technique using a single capillary was applied for determining the binding constant [23] and quantitative determination for analyzing standard and sample within a single run [24,25].…”