Measurement of a continuous distribution of spherical particles by intensity correlation spectroscopy: Analysis by cumulants

1974 ◽  
Vol 61 (5) ◽  
pp. 2134-2138 ◽  
Author(s):  
C. B. Bargeron
1971 ◽  
Vol 4 (5) ◽  
pp. 2033-2050 ◽  
Author(s):  
V. Degiorgio ◽  
J. B. Lastovka

2011 ◽  
Vol 76 (3) ◽  
pp. 207-222 ◽  
Author(s):  
Peter Košovan ◽  
Filip Uhlík ◽  
Jitka Kuldová ◽  
Miroslav Štěpánek ◽  
Zuzana Limpouchová ◽  
...  

We employed the Monte Carlo simulation methodology to emulate the diffusion of fluorescently labeled particles and understand the source of differences between values of diffusion coefficients (and consequently hydrodynamic radii) of fluorescently labeled nanoparticles measured by fluorescence correlation spectroscopy (FCS) and dynamic light scattering (DLS). We used the simulation program developed in our laboratory and studied the diffusion of spherical particles of different sizes, which are labeled on their surface. In this study, we focused on two complicating effects: (i) multiple labeling and (ii) rotational diffusion which affect the fluorescence signal from large particles and hinder the analysis of autocorrelation functions according to simple analytical models. We have shown that the fluorescence fluctuations can be well fitted using the analytical model for small point-like particles, but the obtained parameters deviate in some cases significantly from the real ones. It means that the current data treatment yields apparent values of diffusion coefficients and other parameters only and the interpretation of experimental results for systems of particles with sizes comparable to the size of the active illuminated volume requires great care and precaution.


1976 ◽  
Vol 9 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Måns Ehrenberg ◽  
Rudolf Rigler

A quantitative relationship between polarization properties of fluorescence light and molecular rotational diffusion was first derived by Perrin (1926). His results, which concerned spherical particles, have later been refined to the more complex rotational motion of asymmetric bodies (Memming, 1961; Chuang & Eisenthal, 1972; Ehrenberg & Rigler, 1972; Belford, Belford & Weber, 1972).


1998 ◽  
Vol 111 (2) ◽  
pp. 271-281 ◽  
Author(s):  
C.M. Brown ◽  
N.O. Petersen

Clathrin associated adaptor protein is involved in endocytosis at the plasma membrane (AP-2) and protein sorting at the Golgi membrane (AP-1). There is a great deal of information available on the structure, function and binding characteristics of AP-2, however, there is little quantitative data on the AP-2 distribution at the membrane. Image correlation spectroscopy is a technique which yields number counts from an autocorrelation analysis of intensity fluctuations within confocal microscopy images. Image correlation spectroscopy analysis of the indirect immunofluorescence from AP-2 at the plasma membrane of CV-1 cells shows that AP-2 is in a bimodal distribution consisting of large coated pit associated aggregates of approximately 60 AP-2 molecules, and smaller aggregates containing approximately 20 AP-2 molecules, which we propose are coated pit nucleation sites. Following hypertonic treatment 25% of the AP-2 molecules dissociate from the large AP-2 aggregates and form AP-2 dimers, leaving the remaining AP-2 as large aggregates with approximately 45 molecules. The smaller AP-2 aggregates completely dissociate forming AP-2 dimers. Dispersion of AP-2 with hypertonic treatment is not seen qualitatively because the number of large AP-2 aggregates is unchanged, the aggregates are just 25% smaller. Change in temperature from 37 degrees C to 4 degrees C has no affect on the number of AP-2 aggregates or the AP-2 distribution between the two populations. These data and estimates of the coated pit size suggest that coated pits cover approximately 0.9% of the cell membrane. Combination of image correlation spectroscopy analysis and measurements of the CV-1 cell surface area show that there are approximately 6x10(5) AP-2 molecules per CV-1 cell with approximately 2x10(5) AP-2 molecules within coated pit structures.


2018 ◽  
Vol 89 (12) ◽  
pp. 123902 ◽  
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Timothy P. Lodge ◽  
...  

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