Sedimentation Velocity Analytical Ultracentrifugation Analysis of Marketed Rituximab Drug Product Size Distribution

Accurate nanoparticle (NP) size determination is essential across research domains, with many functions in nanoscience and biomedical research being size-dependent. Although transmission electron microscopy (TEM) is capable of resolving a single NP down to the sub-nm scale, the reliable representation of entire populations is plagued by challenges in providing statistical significance, predominantly due to limited sample counts, suboptimal preparation procedures and operator bias during image acquisition and analysis. Meanwhile alternative techniques exist, but reliable implementation requires a detailed understanding of appendant limitations. Herein, conventional TEM is compared to the size determination of sub-10 nm gold NPs in solution by small-angle X-ray scattering and analytical ultracentrifugation. Form-free Monte Carlo fitting of scattering profiles offers access to a direct representation of the core size distribution while ultracentrifugation sedimentation velocity analysis provides information of the hydrodynamic size distribution. We report a comparison of these three methods in determining the size of quasi-monodisperse, polydisperse and bimodal gold nanoparticles of 2 – 7 nm and discuss advantages and limitations of each technique.

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Faculty Opinions recommendation of Detection of protein aggregates by sedimentation velocity analytical ultracentrifugation (SV-AUC): sources of variability and their relative importance.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1158683.618896 ◽

2009 ◽

Author(s):

Peter Schuck ◽

Huaying Zhao

Keyword(s):

Analytical Ultracentrifugation ◽

Protein Aggregates ◽

Sedimentation Velocity ◽

Relative Importance

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Methodology for determining rom size distribution

Rem Revista Escola de Minas ◽

10.1590/0370-44672014670184 ◽

2014 ◽

Vol 67 (4) ◽

pp. 405-412

Author(s):

Christiane Ribeiro da Silva ◽

Vládia C. G. de Souza ◽

Jair C. Koppe

Keyword(s):

Size Distribution ◽

Distribution Curve ◽

Size Distributions ◽

Sampling Protocol ◽

Product Size ◽

Operational Conditions ◽

Specific Protocol ◽

Open Side ◽

Ore Dressing

A methodology to determine the size distribution curve of the ROM was developed in a Brazilian iron ore mine. The size of the larger fragments was determined taking photographs and setting the scale of the images to analyze their dimensions (length of their edges and areas). This was implemented according to a specific protocol of sampling that involves split and homogenization stages in situ of a considerable quantity of ore (about 259 metric tonnes). During the sampling process, larger fragments were separated and smaller size material was screened. The methodology was developed initially in order to preview the performance of a primary gyratory crusher that is fed directly from trucks. Operational conditions of the equipment such as closed and open-side settings could be adjusted previously, obtaining different product size distributions. Variability of size of the fragments affects subsequent stages of crushing and can increase circulating load in the circuit. This leads to a decrease of productivity or recovery of the ore dressing. The results showed insignificant errors of accuracy and reproducibility of the sampling protocol when applied to friable itabirite rocks.

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