The Effect Of Cell Detachment Methods On The Electrical Properties Of The Cells

Dielectrophoresis (DEP) has gained significance in recent years in various biological applications. This technique is able to detect the dielectric properties of cells, including the conductivity and permittivity of the membrane and cytoplasm by employing non-uniform AC electric fields. Whilst DEP has increasingly been used for cell characterisation, questions have arisen about the validity of cell membrane measurements where the membrane is modified by the protocol, for example in the detachment of adherent cells. 

In order to asses this; we have evaluated the DEP-derived properties using several detachment methods. In this study, seven different methods including six different cell detachment reagents (Trypsin-EDTA 0.25x, Trypsin-EDTA 1x, Dissociation Fluid, Dissociation Buffer and Accutase) and the scraping method were examined through DEP experiments. 3-D electrode microwell DEP chips developed at the University of Surrey was employed in this research to investigate the electrical properties of the cells, and the conductivity and permittivity of membrane and cytoplasm were determined. HN5 cells were cultured in RPMI medium in standard cell culture conditions.

The results revealed that scraping made the most significant effect on cell properties causing a remarkable reduction in membrane conductivity values. However, the membrane conductivity values remained unchanged using the other detachment methods. Trypsin EDTA produced minimum effects on membrane conductivity and permittivity of the cells relative to other cell detachment methods.