Separation of Amino Acids by Aqueous Two-Phase Electrophoresis on the Micro-Pillar Chips

Abstract

A micro-pillar chip is proposed and developed to separate the amino acids, phenylalanine and tryptophan, through the aqueous two-phase system (ATPS). The surface properties of micro-pillars, specifically hydrophobicity and hydrophilicity for separation are also investigated. Because their isoelectic points (pl values) are similar, these amino acids are difficult to separate by general extraction techniques; the ATPS is thus adopted in a micro-system to separate these amino acids and only a few micro liters of sample are required. The results reveal that the various surface properties of micro-pillars distinguish the separation mechanisms and efficiency. When the micro-pillar array is constructed in the ATPS, the separation efficiency is improved. Furthermore, the surface of micro-pillars becomes activated from hydrophobic to hydrophilic, and micro-pillars with a hydrophilic surface increase the separation ability without sample residues. Hence separation is improved on incorporating hydrophilic micro-pillars in the ATPS.

Aqueous Two‐Phase Systems at Large Scale: Challenges and Opportunities

“…In order to maximize the potential of ATPS, optimal systems for the recovery of particular products need to be developed and understood. For this, miniaturization of the ATPS operations can result in a reduced amount of materials and times employed . ATPS have been applied to separate biomolecules inside microdevices.…”

“…ATPS have been applied to separate biomolecules inside microdevices. One of the first successful attempts used isoelectric focusing principles to separate phenylalanine and tryptophan . Using the conductive principles of ATPS and the incorporation of hydrophilic/hydrophobic microcolumns inside the device allowed the separation of these amino acids with similar isoelectric points.…”