DIELECTRIC-SPECTROSCOPY OF MAMMALIAN-CELLS .1. EVALUATION OF THE BIOMASS OF HELA-CELL AND CHO-CELL IN SUSPENSION BY LOW-FREQUENCY DIELECTRIC-SPECTROSCOPY
I. Cerckel et al., DIELECTRIC-SPECTROSCOPY OF MAMMALIAN-CELLS .1. EVALUATION OF THE BIOMASS OF HELA-CELL AND CHO-CELL IN SUSPENSION BY LOW-FREQUENCY DIELECTRIC-SPECTROSCOPY, Cytotechnology, 13(3), 1993, pp. 185-193
The capacitance of suspensions of CHO and HeLa cells (0.5-3 x 10(6) ce
lls/ml) has been measured between 0.2 and 10 MHz. As frequencies decre
ase, there is a continuous increase in capacitance of both the cell su
spension and the spent growth medium free of cells, a phenomenon which
is partially attributed to an increased polarisation of the electrode
s. At a given frequency, subtraction of the capacitance of the spent m
edium from that of the cell suspension allows one to determine the cap
acitance of the cells only. The intensity of this signal varies linear
ly with the biomass and cell size. At low frequencies such as those us
ed in this study (0.25 MHz), where sensitivity is the highest, concent
rations as low as 0.5 x 10(6) cells/ml can be accurately measured. Sug
gestions are made how to make these measures on-line, non-invasive and
in real time.