title: Photon counting histogram: one-photon excitation.
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 imoroved model, which is based on the correction to the observation volume profile for the out-of-focus emission. We demonstrate that this model is able to resolve different species present under a wide range of conditions. Attention is given to how this model allows the examination of the effects of different instrumental setups on the resolvability.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Perroud
authors.forename: Richard N
authors.initials: RN
authors.lastname: Zare