Optical set-up for the discovering of distant interaction between cells monolayers is proposed. This set-up allows to show with high degree of trustworthiness, that animal cells monolayer (monolayer-inductor) having its mitotic activity as a result of outer influence emits electromagnetic radiation that causes adequate alterations in the cells monolayer (monolayer-detector) placed at some distance from monolayer- inductor. It is established that distant interaction between cells monolayers (mitosis synchronization) is realized by the radiation of visible spectral range. The effect of distant synchronization mitosis in a inductor-detector pair observes both in the case of cells stimulation mitotic activity and in the case of activity inhibition. The mitosis synchronization is absent when a filter absorbing light in visible spectral range is used or optical contact between monolayer-inductor and monolayer-detector is disturbed.