Separation of Human Mammary Epithelial Cells Using a Dielectrophoresis-based Microfluidic Device

Analysis of Temperature Field in the Dielectrophoresis-Based Microfluidic Cell Separation Device

“…The syringe set on the syringe pump was connected to the sample solution introduction port at the microfluidic upstream end via a silicone tube. After the syringe was filled with 5 mL of sample solution and the sample solution flowed into the microfluidic channel at a constant flow rate, using the syringe pump to degas the microfluidic channel, the wave generator was switched on and an AC voltage of 20 V pp was applied to the device [17]. Fluorescence images were acquired using a laser beam with an excitation wavelength of 559 nm and a bandpass filter with a wavelength range of 570-670 nm.…”

“…The experiments were performed by varying the frequency f to f = 20, 200 and 2000 kHz and the sample solution flow rate Q to Q = 5, 10 and 20 mL/h. For the values of f and Q, the same values as those used in the cell separation experiments [17] were used.…”

“…Rhodamine B, which is widely used in the LIF method, was used as the fluorescent dye [18,19]. A 300 mM mannitol solution, widely used for cell separation, was used as the solvent for the sample solution [17,20,21] and the solution conductivity was prepared to σ = 1 × 10 −3 S/m using cell culture medium, and the final concentration of Rhodamine B (Sigma 83695-250MG; ex 553 nm, em 627 nm) was set at 20 µ M [22,23].…”

“…For the electrode width and spacing, 3~4 times the cell diameter (~16 mm) [24] was thought to be desirable for the effective separation of cells [24,25]. Therefore, the electrode width and spacing were taken as 50 mm [17]. The electrode substrates were fabricated by vacuum deposition of a 300 nm-thick aluminum film onto a glass planar plate of the size 50 × 90 mm using standard photolithography.…”

“…However, it has the advantage of significantly reducing the heat generation. Recently, the authors developed a microfluidic cell separation device adopting the AC dielectrophoresis, and achieved a cell separation ratio of over 90% for live and dead human-mammary cells suspended in a low-conductivity (σ = 1 mS/m) mannitol solution [17]. In this study, the temperature field analysis in the developed device under the condition of the cell separation operation was conducted to evaluate the temperature rise that has baneful influence on cell viability.…”