ABSTRACT
The aqueous two-phase system (ATPS) composed of polymers is often used for the separation of cells and other biomolecules due to its compatibility with bioparticles. In this paper, an ATPS composed of 5% polyethylene glycol (PEG) and 11% dextran was used to study the electrokinetic (EK) movement of polystyrene particles at the interface. The results show that the EK velocities of particles at the ATPS interface both decrease with the increase in particle size. EK velocity of the droplet formed by one phase (PEG or dextran) in the other phase was investigated, indicating that the surface of the dextran droplet in the PEG-rich phase is negatively charged and the surface of the PEG droplet in the dextran-rich phase is positively charged. The experimental results provide a method for bioparticle separation based on different electrokinetic velocities at the ATPS interface.
