Microfluidic Aqueous Two-Phase Systems
Aqueous Two-Phase Systems (ATPS) are an established technology that have been used to separate out biologically important particles such as biomolecules, organelles, and whole cells. ATPS are formed by mixing polymers such as polyethylene glycol (PEG) and dextran (Dex) at sufficiently high concentrations such that two immiscible phases are formed. Traditional macroscale ATPS are performed in test tubes and require relatively large reagent volumes and are limited to a vertical configuration where the interface lies perpendicular to the direction of gravity. Settling becomes problematic for larger particles and the long diffusion distances mean that separations require significant time. Recent advances in microfluidics systems allow novel configurations of ATPS that are impossible with traditional techniques. Examples are nanoliter ATPS droplets or parallel streams of ATPS which enable new applications and improvements over traditional separations. Microscale ATPS can separate particles in seconds instead of hours using only microliters of reagent.
KeywordsAmino acids Aqueous two-phase systems (ATPS) Bacteriorhodopsin (BR) Bovine serum albumin (BSA) Carbonic anhydrase Chinese hamster ovary (CHO) Dextran DNA Droplets Glutathione S-transferase Green fluorescent protein acgfp1 Human erythrocytes (RBC) Human leukocytes (WBC) Human T lymphoma (Jurkat) Immunoglobulin G (IgG) Microfluidic Mycotoxin ochratoxin A (OTA) Ovalbumin Partition coefficient Partitioning Plant aggregates (strawberry) Polyethylene glycol Separation α-Amylase β-Galactosidase
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