Estimation of morphological characteristics of single particles from light scattering data in flow cytometry

1994 ◽  
Vol 43 (7) ◽  
pp. 1115-1124 ◽  
Author(s):  
V. P. Maltsev
Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 124
Author(s):  
Jaco Botha ◽  
Haley R. Pugsley ◽  
Aase Handberg

Flow cytometry remains a commonly used methodology due to its ability to characterise multiple parameters on single particles in a high-throughput manner. In order to address limitations with lacking sensitivity of conventional flow cytometry to characterise extracellular vesicles (EVs), novel, highly sensitive platforms, such as high-resolution and imaging flow cytometers, have been developed. We provided comparative benchmarks of a conventional FACS Aria III, a high-resolution Apogee A60 Micro-PLUS and the ImageStream X Mk II imaging flow cytometry platform. Nanospheres were used to systematically characterise the abilities of each platform to detect and quantify populations with different sizes, refractive indices and fluorescence properties, and the repeatability in concentration determinations was reported for each population. We evaluated the ability of the three platforms to detect different EV phenotypes in blood plasma and the intra-day, inter-day and global variabilities in determining EV concentrations. By applying this or similar methodology to characterise methods, researchers would be able to make informed decisions on choice of platforms and thereby be able to match suitable flow cytometry platforms with projects based on the needs of each individual project. This would greatly contribute to improving the robustness and reproducibility of EV studies.


2011 ◽  
Vol 79A (7) ◽  
pp. 570-579 ◽  
Author(s):  
Dmitry I. Strokotov ◽  
Alexander E. Moskalensky ◽  
Vyacheslav M. Nekrasov ◽  
Valeri P. Maltsev

Fractal colloid aggregates are studied with both static and dynamic light scattering. The dynamic light scattering data are scaled onto a single master curve, whose shape is sensitive to the structure of the aggregates and their mass distribution. By using the structure factor determined from computer-simulated aggregates, and including the effects of rotational diffusion, we predict the shape of the master curve for different cluster distributions. Excellent agreement is found between our predictions and the data for the two limiting régimes, diffusion-limited and reaction-limited colloid aggregation. Furthermore, using data from several completely different colloids, we find that the shapes of the master curves are identical for each régime. In addition, the cluster fractal dimensions and the aggregation kinetics are identical in each régime. This provides convincing experimental evidence of the universality of these two régimes of colloid aggregation.


2018 ◽  
Vol 8 (9) ◽  
pp. 1674
Author(s):  
Wengang Chen ◽  
Wenzheng Xiu ◽  
Jin Shen ◽  
Wenwen Zhang ◽  
Min Xu ◽  
...  

By using different weights to deal with the autocorrelation function data of every delay time period, the information utilization of dynamic light scattering can be obviously enhanced in the information-weighted constrained regularization inversion, but the denoising ability and the peak resolution under noise conditions for information-weighted inversion algorithm are still insufficient. On the basis of information weighting, we added a penalty term with the function of flatness constraints to the objective function of the regularization inversion, and performed the inversion of multiangle dynamic light scattering data, including the simulated data of bimodal distribution particles (466/915 nm, 316/470 nm) and trimodal distribution particles (324/601/871 nm), and the measured data of bimodal distribution particles (306/974 nm, 300/502 nm). The results of the inversion show that multiple-penalty-weighted regularization inversion can not only improve the utilization of the particle size information, but also effectively eliminate the false peaks and burrs in the inversed particle size distributions, and further improve the resolution of peaks in the noise conditions, and then improve the weighting effects of the information-weighted inversion.


2018 ◽  
Author(s):  
Molla Islam ◽  
Maddie Tumbarello ◽  
Andrew Lyon

<div>We demonstrated the deswelling induced morphological change in dual pH and Temperature responsive ultra-low crosslinked Poly (N-isopropyl acrylamide)-co-acrylic acid microgels. The responsivity with pH and temperature were studied by light scattering and atomic force microscopy. Light scattering data suggest that at pH 4.5 the microgels undergo multiple transitions associated with collapse of pNIPAm-rich segments and repulsion between the AAc-rich segments. The evolution of punctate structures around the periphery or throughout the whole microgels at pH 4.5 and 6.5 respectively was revealed by AFM, further illustrating the heterogeneous deswelling present in the ionized copolymer microgels.</div><div>The impact of this study and understanding how ionization state of copolymer dictates the overall structural properties of microgels will widen our understanding for their applications in biotechnology</div><div><b><br></b></div>


2009 ◽  
Vol 4 (2) ◽  
pp. 61-68
Author(s):  
Dmitriy Strokotov ◽  
Yuriy Pichugin ◽  
Maxim Yurkin ◽  
Mariya Gridina ◽  
Oleg Serov ◽  
...  

In this manuscript we propose two methods to solve inverse light scattering problem for single particles, which can be described as a coated sphere. The efficiency of the methods is illustrated by characterization of lymphocytes and stem cells using light scattering patterns obtained with scanning flow cytometer. Both methods, spectral and global optimization, were used to obtain diameters and refractive indices of the cytoplasm and the nucleus of mice embryo stem cells and human lymphocytes. These results agree with data obtained from other studies. Determination of these parameters is important for diagnostics of pathological states of lymphocytes and differentiation status of embryo stem cells. Moreover, methods described in this manuscript are applicable to all mononuclear cells. We also considered limitations of these methods and their possible improvements.


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