A method for deciding whether two experimental fluorescence anisotropy decay curves are significantly different.

We describe a method to compare two fluorescence anisotropy decay curves. After numerical deconvolution of both decays by a non a priori method [1], their difference, D, is considered. The variance is computed for each point of D. A confidence interval is defined which allows a decision to be made as to the significance of D. Information on the time range in which the changes of the fluorescence anisotropy decay occur is directly available. This analysis is particularly well suited for following the perturbations induced by an effector. It has been tested on 3-phosphoglycerate kinase in the presence and in the absence of ATP and 3-phosphoglycerate. We consider that this method leads to a significant improvement in the application of time resolved depolarization experiments.