Traceable Impedance-Based Dispensing and Cloning of Living Single Cells and Impedance-Based Single-Cell Pipetting

Volume 25 Issue 3, June 2020

Dave Pechter discusses with Georges Muller & Yann Barrandon their two featured research articles, "Traceable Impedance-Based Dispensing and Cloning of Living Single Cells" and "Impedance-Based Single-Cell Pipetting."

Traceable Impedance-Based Dispensing and Cloning of Living Single Cells: Single-cell cloning is essential in stem cell biology, cancer research, and biotechnology. Regulatory agencies now require an indisputable proof of clonality that current technologies do not readily provide. Here, we report a one-step cloning method using an engineered pipet combined with an impedance-based sensing tip. This technology permits the efficient and traceable isolation of living cells, stem cells, and cancer stem cells that can be individually expanded in culture and transplanted.

Impedance-Based Single-Cell Pipetting: Many biological methods are based on single-cell isolation. In single-cell line development, the gold standard involves the dilution of cells by means of a pipet. This process is time-consuming as it is repeated over several weeks to ensure clonality. Here, we report the modeling, designing, and testing of a disposable pipet tip integrating a cell sensor based on the Coulter principle. We investigate, test, and discuss the effects of design parameters on the sensor performances with an analytical model. We also describe a system that enables the dispensing of single cells using an instrumented pipet coupled with the sensing tip. Most importantly, this system allows the recording of an impedance trace to be used as proof of single-cell isolation. We assess the performances of the system with beads and cells. Finally, we show that the electrical detection has no effect on cell viability.