Exposures were performed in a shielded room (made of 12.5-mm thick low-carbon steel sheets) on a standard clean bench for tissue culture, and metal surfaces surrounding the horn antenna were covered with MW-absorbing material to minimize reflections. MW generator, power meter, and spectrum analyzer were located outside. [Rojavin et al., 1997, 1998]
Cell cultures in the 15-mm wells of a standard 24-well plate, placed on top of the antenna, were exposed, one well at a time. Four corner wells of each plate were loaded with keratinocyte suspension. Two wells were exposed to MW and two were left as plate controls.
The SAR was determined from the initial rate of temperature rise measured using a calibrated 0.1-mm thermocouple positioned in contact with the bottom of the well. The incident power density was calculated using the relationship described in [Gandhi and Riazi, 1986] from the SAR, density, penetration depth, and power reflection coefficient. The latter two quantities were measured using the method described in [Alekseev and Ziskin, 2000].