He-Ne laser (632.8 nm) pre-irradiation gives protection against DNA damage induced by a near-infrared trapping beam.

We report the results of a study carried out to investigate the effect of He-Ne laser (632.8 nm) pre-irradiation on DNA damage induced by continuous wave 1064 nm trapping beam exposure in MCF-7 cells. A significant decrease in % tail DNA (p < 0.05) was observed in MCF-7 cells pre-exposed to He-Ne laser beam. The dependence of the induced protection against 1064 nm trapping beam irradiation induced DNA damage on the time interval between the two irradiations as well as the He-Ne laser pre-irradiation parameters is presented.