A simple and highly stable free-flow electrophoresis device with thermoelectric cooling system.

Complex assembly, inconvenient operations, poor control of Joule heating and leakage of solution are still fundamental issues greatly hindering application of free-flow electrophoresis (FFE) for preparative purpose in bio-separation. To address these issues, a novel FFE device was developed based on our previous work. Firstly, a new mechanical structure was designed for compact assembly of separation chamber, fast removal of air bubble, and good anti-leakage performance. Secondly, a highly efficient thermoelectric cooling system was used for dispersing Joule heating for the first time. The systemic experiments revealed the three merits: (i) 3min assembly without any liquid leakage, 80 times faster than pervious FFE device designed by us or commercial device (4h); (ii) 5s removing of air bubble in chamber, 1000-fold faster than a normal one (2h or more) and (iii) good control of Joule heating by the cooling system. These merits endowed the device high stable thermo- and hydro-dynamic flow for long-term separation even under high electric field of 63V/cm. Finally, the developed device was used for up to 8h continuous separation of 5mg/mL fuchsin acid and purification of three model proteins of phycocyanin, myoglobin and cytochrome C, demonstrating the applicability of FFE. The developed FFE device has evident significance to the studies on stem cell, cell or organelle proteomics, and protein complex as well as micro- or nano-particles.

Mathematical model and dynamic computer simulation on free flow zone electrophoresis.

In this paper, a mathematical model was proposed for calculating physico-chemical parameters and simulating the separation process of solutes in free-flow zone electrophoresis (FFZE). Computer software was developed and implemented in a Delphi XE2 environment based on the model, which comprises zone electrophoresis, electrolyte solution, hydrodynamics and diffusion as well as conversion equations. The simulation results reveal that (i) the software is capable of simulating a dynamic process of FFZE properly; (ii) the software can simulate operation parameters (e.g., electric field, flow rate and pH value) for experimental optimization; (iii) the simulator is able to display the final electropherogram of numerous analytes in FFZE; and (iv) the electropherogram of FFZE can be automatically converted to that of capillary zone electrophoresis. In order to verify the rationality and reliability of this software, the relevant experiments were conducted and further compared with the simulations. The comparisons demonstrated the high agreement between the simulations and the experiments as well as those cited from the relevant references. In addition, effective mobility, diffusion coefficient and concentration of solutes can be conveniently gained via the software. The developed mathematical model and designed software have evident significance for the optimization of experimental conditions and basic physico-chemical parameters in FFZE.