A detailed description of the RTL device and its environmental controls has been given in several publications [Moros et al., 1998 and 1999; Pickard et al., 1999 and 2000].
|Chamber||The radial transmission line (RTL) was formed by two horizontal parallel electrically conducting plates. A central conical aluminium antenna emitted TEM waves radially outward that were terminated by an annulus of RF-absorbing foam. The thermally conductive aluminium bottom plate (6 mm thick) minimised temperature gradients among the exposed flasks placed equidistantly around the antenna. The temperature of the culture media during RF and sham exposure was 37 ± 0.3°C [Moros et al., 1999].|
|Setup||Both powered and sham RTLs were loaded with 16 T75 culture flasks containing 40 ml of culture medium, 15 of them being dummy flasks.|
|Sham exposure||A sham exposure was conducted.|
|Additional info||For positive control, cultured cells were first maintained in the incubator for an additional 24 h (to mirror the length of RF exposure), then irradiated with 0.68 Gy of X-rays, and afterwards placed back into the incubator for a 4-h recovery. Another identically treated flask of cells was sham exposed in the X-ray irradiator.|
The number of gene expression changes induced by irradiation was not greater than the number of false positives expected based on a sham exposure versus sham exposure comparison.
In contrast, the X-rays radiated samples showed higher number of gene expression changes than in the sham exposure versus sham exposure comparison.