Accumulation and Desorption of Biomolecules at Liquid-Liquid Interfaces in Aqueous Two-Phase Systems

• Applicant: Professor Dr. Steffen Hardt
• Subject Area: Analytical Chemistry ; Chemical and Thermal Process Engineering
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 253710362

Long-chain DNA molecules or proteins will be accumulated electrophoretically at the phase boundary in an aqueous two-phase system. Via the subsequent increase of the electric field strength, the desorption of the molecules into the adjacent phase will be initiated. In the proposed project it should be studied in how far different protein species or long-chain DNA molecules can be separated that way. For that purpose a dedicated microfluidic system will be designed and fabricated. The stretching of DNA molecules at the phase boundary will be characterized by epifluorescence microscopy. Different methods for achieving a separation of dissimilar molecules will be studied. In a special configuration a liquid lamella is bridged by the stretched DNA-molecules. The lamella width will be chosen such that ideally only the larger molecules can penetrate into the neighboring phase. Moreover, similar experiments will be performed with proteins, where the goal is to achieve a separation according to specific properties such as their mass or isoelectric point. In the first place, the proposed project should serve to demonstrate novel mechanisms for the separation and purification of biomolecular mixtures. Besides that, the experiments will produce data that could lead to a better understanding of the morphology of the phase boundary in aqueous two-phase systems.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Detlev Belder