The quantitative studies with organisms of different complexity (HeLa cells, yeast
organisms, E coli bacteria) to prove or disprove the stimulating action of low-intensity
visible light are presented. The stimulation of DNA synthesis in HeLa cells was observed
for four spectral intervals with maxima at near 400, 620, 680 and 760 nm. The red light
stimulates the growth of yeast (Saccharomycodes ludwigii) and E coli in exponential
growth phase. The action spectrum of monochromatic light on the growth of these
organisms in the red region is very similar to that for HeLa cells.
Biostimulating Action of
Low-Intensity Monochromatic
Visible Light: Is it Possible?