yanjiang's histogram [2 articles]

Abstract

The photon counting histogram (PCH) analysis is a fluorescence fluctuation method that is able to characterize the brightness and concentration of different fluorescent species present in a liquid sample. We find that the PCH model using a three-dimensional Gaussian observation volume profile is inadequate for fitting experimental data obtained from a confocal setup with one-photon excitation. We propose an improved model, which is based on the correction to the observation volume profile for the out-of-focus emission. We demonstrate that this model ...

Abstract

Fluorescence correlation spectroscopy (FCS) is generally used to obtain information about the number of fluorescent particles in a small volume and the diffusion coefficient from the autocorrelation function of the fluorescence signal. Here we demonstrate that photon counting histogram (PCH) analysis constitutes a novel tool for extracting quantities from fluorescence fluctuation data, i.e., the measured photon counts per molecule and the average number of molecules within the observation volume. The photon counting histogram of fluorescence fluctuation experiments, in which few molecules ...