What do photons do to fluorescently stained DNA in confinement?

Paper in proceeding, 2014

We have studied a selection of factors influencing the damage of DNA in nanochannels during fluorescence imaging. For cutting and nicking of DNA we show that the DNA is shortened during imaging. To avoid photodamage over the course of several hours of a typical experiment, we demonstrate the importance of an oxygen free gas to propel the buffer solution through the device. Finally, by varying the size of the channels, we show indications that higher DNA concentrations lead to higher rates of photodamage necessitating a balance between needs for highly stretched DNA and needs for long measurement times.