Introduction to the dielectric estimation of cellular biomass in real time, with special emphasis on measurements at high volume fractions

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

“…135 We also note a number of approaches to the development of coagulometry based on the measurement of the passive electrical properties of the sample, [136][137][138][139][140][141][142] a strategy that we ourselves have found useful, 143 with radio-frequency measurements of cellular properties having a particular value. [144][145][146][147] Finally, fibrin scatters light much more than does fibrinogen such that turbidimetry is often used to detect its formation (e.g. ref.…”

Process control in cell culture technology using dielectric spectroscopy

“…2 describes the dependency of the capacitance signal of a biological sample with spherical cells as a function of the radio frequency. The increase in capacitance from high to low frequencies displays a sigmoid shape and is known as the ß-dispersion [Cannizzaro et al, 2003, Davey et al, 1993a, Esteban et al, 2008. At low frequencies, the polarization process is slow, so that the resulting capacity is high.…”

“…The detailed mathematical description of DS has been discussed in the literature and in textbooks [Arnold, 2001, Coster et al, 1996, Davey et al, 1993a, Davey et al, 1993b, Marszalek et al, 1990, Pethig and Kell, 1987, Barsoukov and Macdonald, 2005]. An overview is given below.…”

Optimization of Insect Cell Based Protein Production Processes - Online Monitoring, Expression Systems, Scale Up

“…The observed drop in the measured capacitance from low to high frequencies exhibits a sigmoid shape which is also known as the β-dispersion spectrum [102].…”

“…Thus, dead or leaking cells are not captured by this technology [103]. Additionally, the capacitance signal is reported to be insensitive to gas bubbles and microcarriers facilitating the monitoring of cell culture processes in common sparged as well as fixed bed bioreactors [102,104,105]. However, very high volume fractions of non-biomass materials close to the sensor may influence the capacitance signal since the polarizable cells are replaced by non-polarizable materials [102].…”