Use of a Bacterial Gene Expression System for Mutation Repairing (UMU System) to Evaluate Damage in DNA Molecules Resulting from Exposure to Extremely Low Frequency Magnetic Field

The vicious effect of extremely low frequency magnetic field (ELFMF) on living biological cells was investigated by 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 the DNA Salmonella  typhimirinum TA1535 (pSK1002), a mutagen-sensitive bacterium that possesses a gene expression system (a umu operan) for highly-sensitive SOS response to damage m DNA molecules wit a β-galactosidase gene as a reporter gene, was exposed to ELFMF(1.2µT) in a specially designed magnetic field loading chamber. The experimental results showed that the umu assay could be effectively applied to evaluate the damage in DNA molecules by ELFMF. However, not significant difference was detected in the intesity of umu gene expression using β-galactosidase reporting system under the experimental conditions.