2-STATE DYNAMICS OF SINGLE BIOMOLECULES IN SOLUTION

Recent fluorescence decay experiments on an ensemble of chromophores, each tethered to a large DNA molecule, show a biexponential relaxation in time. Experiments on individual molecules also show biexponential relaxation, but with a wide distribution of the relative weights of th e two components. This indicates that on the time scale of the single- molecule experiments, the molecules are jumping between two possible s tates. We show that a stochastic two-state jump model can provide a qu antitative description of these experiments. Recent similar experiment s on single tRNA molecules are also analyzed with the model. (C) 1998 Elsevier Science B.V. All rights reserved.