Inhibition of yeast growth during long term exposure to laser light around 1064 nm

Abstract

We have studied the effect of a 1070 nm continuous wave Ytterbium fiber laser on exponentially growing Saccharomyces cerevisiae yeast cells over a span of 4 hours. The cells were immobilized onto Concanavalin A covered microscope slides and the growth was measured using the area increase of the cells in 2D. Using a continuous dual beam plane wave with a uniform spatial intensity distribution, we found that a continuous radiant flux through a single cell as low as 0.5 mW in 1.5 hours significantly changed the growth and division rate of S. cerevisiae. With the dual beam setup used we were able to successfully manipulate single S. cerevisiae cells in 3 dimensions with a minimum flux thorough the cell of 3.5 mW. In the regime investigated from 0.7 mW to 2.6 mW we found no threshold for the photo damage, but rather a continuous response to the increased accumulated dose.