Electromagnetic effects of non-ionizing radiation on a cell nucleus and cell assembly

Electromagnetic radiation can be classified into ionizing and non-ionizing varieties. In this study, we designed two-beam optical tweezers to demonstrate that non-ionizing radiation could induce intercellular attraction between human red blood cells by its electromagnetic nature. An infrared spot in the optical tweezers was irradiated on an assembly of RBCs to polarize them and derived attractive interaction; the other visible spot was used to gauge the sub-pN intercellular interaction. It was found that 34~57 μW/μm² IR radiation could cause attraction among a 3~4 RBC cluster; the power density was equivalent to only 10^-3~10^-2 of that used in a CD drive. We found that the intercellular interaction was approximately proportional to the power density of the IR radiation. Besides, we observed 36 minutes of 75 μW/μm² IR radiation could shrink the nucleus of an onion cuticle cell. Based on these results, we established a model to describe the electromagnetic effect of non-ionizing radiation on a cell assembly by inducing the micro-stresses transverse to its propagation axis.