Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.

Fluorescence fluctuation spectroscopy (FFS) refers to techniques that analyze fluctuations in the fluorescence emitted by fluorophores diffusing in a small volume and can be used to distinguish between populations of molecules that exhibit differences in brightness or diffusion. For example, fluores...

Full description

Bibliographic Details
Main Authors: Nathan Scales, Peter S Swain
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2019-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0226063
_version_ 1819007955255689216
author Nathan Scales
Peter S Swain
author_facet Nathan Scales
Peter S Swain
author_sort Nathan Scales
collection DOAJ
description Fluorescence fluctuation spectroscopy (FFS) refers to techniques that analyze fluctuations in the fluorescence emitted by fluorophores diffusing in a small volume and can be used to distinguish between populations of molecules that exhibit differences in brightness or diffusion. For example, fluorescence correlation spectroscopy (FCS) resolves species through their diffusion by analyzing correlations in the fluorescence over time; photon counting histograms (PCH) and related methods based on moment analysis resolve species through their brightness by analyzing fluctuations in the photon counts. Here we introduce correlated photon counting histograms (cPCH), which uses both types of information to simultaneously resolve fluorescent species by their brightness and diffusion. We define the cPCH distribution by the probability to detect both a particular number of photons at the current time and another number at a later time. FCS and moment analysis are special cases of the moments of the cPCH distribution, and PCH is obtained by summing over the photon counts in either channel. cPCH is inherently a dual channel technique, and the expressions we develop apply to the dual colour case. Using simulations, we demonstrate that two species differing in both their diffusion and brightness can be better resolved with cPCH than with either FCS or PCH. Further, we show that cPCH can be extended both to longer dwell times to improve the signal-to-noise and to the analysis of images. By better exploiting the information available in fluorescence fluctuation spectroscopy, cPCH will be an enabling methodology for quantitative biology.
first_indexed 2024-12-21T00:32:48Z
format Article
id doaj.art-d2bcc73d43fb44b281116e1a3d0ea915
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-12-21T00:32:48Z
publishDate 2019-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-d2bcc73d43fb44b281116e1a3d0ea9152022-12-21T19:21:51ZengPublic Library of Science (PLoS)PLoS ONE1932-62032019-01-011412e022606310.1371/journal.pone.0226063Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.Nathan ScalesPeter S SwainFluorescence fluctuation spectroscopy (FFS) refers to techniques that analyze fluctuations in the fluorescence emitted by fluorophores diffusing in a small volume and can be used to distinguish between populations of molecules that exhibit differences in brightness or diffusion. For example, fluorescence correlation spectroscopy (FCS) resolves species through their diffusion by analyzing correlations in the fluorescence over time; photon counting histograms (PCH) and related methods based on moment analysis resolve species through their brightness by analyzing fluctuations in the photon counts. Here we introduce correlated photon counting histograms (cPCH), which uses both types of information to simultaneously resolve fluorescent species by their brightness and diffusion. We define the cPCH distribution by the probability to detect both a particular number of photons at the current time and another number at a later time. FCS and moment analysis are special cases of the moments of the cPCH distribution, and PCH is obtained by summing over the photon counts in either channel. cPCH is inherently a dual channel technique, and the expressions we develop apply to the dual colour case. Using simulations, we demonstrate that two species differing in both their diffusion and brightness can be better resolved with cPCH than with either FCS or PCH. Further, we show that cPCH can be extended both to longer dwell times to improve the signal-to-noise and to the analysis of images. By better exploiting the information available in fluorescence fluctuation spectroscopy, cPCH will be an enabling methodology for quantitative biology.https://doi.org/10.1371/journal.pone.0226063
spellingShingle Nathan Scales
Peter S Swain
Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
PLoS ONE
title Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
title_full Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
title_fullStr Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
title_full_unstemmed Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
title_short Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms.
title_sort resolving fluorescent species by their brightness and diffusion using correlated photon counting histograms
url https://doi.org/10.1371/journal.pone.0226063
work_keys_str_mv AT nathanscales resolvingfluorescentspeciesbytheirbrightnessanddiffusionusingcorrelatedphotoncountinghistograms
AT petersswain resolvingfluorescentspeciesbytheirbrightnessanddiffusionusingcorrelatedphotoncountinghistograms