Fluorescence lifetime measurements of <i>in vitro</i> λ-DNA solutions of varying viscosity.

<p>We determine the mean fluorescence lifetime dependence of Hoechst 33342 bound to λ-DNA in solutions of varying viscosity glycerol-ethylene glycol solutions. We see a strong dependence of the mean fluorescence lifetime on viscosity over the range here. Viscosity measurements for the glycerol-ethylene solutions were determined using a Discovery Hybrid Rheometer-2. Statistical comparisons made by Student’s t-test, with *p<0.05, **p<0.025, ***p<0.01 and ****p<0.001. All statistical comparisons of the magnitudes are with the previous point unless otherwise indicated by lines. The viscosity power-law fit dependence of the mean fluorescence lifetime, based on the known phenomenological relationship between fluorescence lifetime and viscosity, was determined using ANOVA (p<<<0.001).