Analysis of fluorescence decay by the maximum entropy method: influence of noise and analysis parameters on the width of the distribution of lifetimes

Abstract

Maximum entropy method (MEM) was used for resolving multiple decay components in synthetic and experimental time-resolved fluorescence decay. The distribution of lifetimes is unimodal or multimodal and there is a one-to-one correspondence between the results of MEM and discrete exponential analysis. The distribution is symmetric in log(t) space and approximately Gaussian. The width of the distribution is sensitive to several factors related to the experimental or analysis conditions, such as the peak count, discretization in τ space, completeness of decay and the χ² stopping criterion. Therefore, the width of the distribution cannot be a useful indicator of the extent of heterogeneity of lifetimes in a sample of a complex biological system.