Yeast Cell Growth Monitoring Using Microwave Measurements Correlated to Optical Absorbance

Requiring neither labels nor complicated data processing technique, electrical techniques are very attractive and promising in biological/pharmaceutical research. Traditionally, impedance spectroscopy in the kHz frequency range is used for measuring cell growth and other dynamic cell culture responses. This paper reports, for the first time, real-time in vivo monitoring of yeast cell growth up to microwave frequencies. To validate the approach, we here report on the correlation of microwave sensing to the more commonly used approach that is based on optical absorbance. Measurements on four cell suspensions of known concentrations, and on BY 4741 cell growth are successfully performed. Although more studies are required to further understand the events recorded by the monitoring procedure, the presented measurement results suggest that the proposed real-time microwave characterization technique is a faster and noninvasive option for early cell growth detection. Moreover, it is believed that this technique can be readily extended to mammalian cells.