Separation of Animal Cells in Microfluidic Device Using Aqueous Two-Phase Extraction

초록

Monitoring of animal cell population such as viability and number of cells is important for a diagnosis of the health of a culture. The automated and rapid monitoring method assists better control of culture conditions. In this study, fractionation of live and dead CHO-K1 (Chinese Hamster Ovary) cells has bean realized on microfluidic devices by aqueous two-phase extraction method. The aqueous two-phase system (ATPS) gives favorable conditions for the biomolecules during separation process, because of high content of water in both phases. Normally, content of water in each phase is more than 80% in ATPS. Polyethylene glycol 8000 (PEG8000) and dextran T500 [1] were selected as a basal aqueous two-phase forming polymers. Microfluidic devices were made of Poly (dimethyl siloxane) (PDMS) [2, 3]. Overall surface properties of the animal cell, such as hydrophobicity and surface net charge affect the partitioning characteristics in ATPS. The CHO K-1 cells were distributed to PEG phase at pHs below 7.0 more than dextran phase, because of the increased hydrophobicity of the cell surfaces caused by a loss of charge. Live cells were distributed to PEG phase up to 95% at pH 6.6 while dead cells preferred dextran phase.