Evaluation of damage in DNA molecules resulting from very-low-frequency magnetic fields by using bacterial mutation repairing genetic system

The effect of very-low-frequency magnetic fields (VLFMF) on living biological cells was investigated using a highly sensitive mutagenesis assay method. A bacterial gene expression system for mutation repair (umu system) was used for the sensitive evaluation of damage in DNA molecules. Salmonella typhimurium TA1535/pSK1002 were exposed to VLFMF (20 kHz, 600 /spl mu/T, and 60 kHz, 100 /spl mu/T) in a specially designed magnetic field exposure chamber. The experimental results showed the possibility of applying the umu assay for sensitive and effective evaluation of damage in DNA molecules. No significant difference was observed in the umu gene expression intensity under exposure to magnetic field of 20 kHz, 600 /spl mu/T, and 60 kHz, 100 /spl mu/T.