Small-volume extensional rheology of concentrated protein and protein-excipient solutions

Soft Matter ◽

10.1039/d1sm01253c ◽

2021 ◽

Author(s):

Kathleen T. Lauser ◽

Amy L. Rueter ◽

Michelle A. Calabrese

Keyword(s):

Shear Flow ◽

Small Volume ◽

Extensional Rheology ◽

Protein Formulations ◽

Extensional Flows ◽

Undesirable Behavior

We develop a small-volume extensional rheology device to measure concentrated protein formulations, and show that excipients intended to stabilize proteins in shear flow can cause undesirable behavior in extensional flows.

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An experimental and simulation study of dilute polymer solutions in exponential shear flow: Comparison to uniaxial and planar extensional flows

Journal of Rheology ◽

10.1122/1.1346599 ◽

2001 ◽

Vol 45 (2) ◽

pp. 321-349 ◽

Cited By ~ 5

Author(s):

Thomas C. B. Kwan ◽

Nathanael J. Woo ◽

Eric S. G. Shaqfeh

Keyword(s):

Shear Flow ◽

Simulation Study ◽

Polymer Solutions ◽

Dilute Polymer Solutions ◽

Extensional Flows

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Protamine-DNA interaction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081863 ◽

1978 ◽

Vol 36 (2) ◽

pp. 200-201

Author(s):

D.P. Bazett-Jones ◽

F.P. Ottensmeyer

Keyword(s):

Small Volume ◽

Double Helix ◽

Dna Interaction ◽

Dark Field ◽

Sperm Head ◽

Nuclear Proteins ◽

Field Electron Microscopy ◽

Dark Field Electron ◽

Dna Double Helix ◽

Positively Charged

Dark field electron microscopy has been used for the study of the structure of individual macromolecules with a resolution to at least the 5Å level. The use of this technique has been extended to the investigation of structure of interacting molecules, particularly the interaction between DNA and fish protamine, a class of basic nuclear proteins of molecular weight 4,000 daltons.Protamine, which is synthesized during spermatogenesis, binds to chromatin, displaces the somatic histones and wraps up the DNA to fit into the small volume of the sperm head. It has been proposed that protamine, existing as an extended polypeptide, winds around the minor groove of the DNA double helix, with protamine's positively-charged arginines lining up with the negatively-charged phosphates of DNA. However, viewing protamine as an extended protein is inconsistent with the results obtained in our laboratory.

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The Theoretical Contrast in Scanning and Conventional High Resolution Microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062762 ◽

1969 ◽

Vol 27 ◽

pp. 170-171

Author(s):

E. Zeitler ◽

M. G. R. Thomson

Keyword(s):

Small Volume ◽

Volume Element ◽

Optical Processing ◽

Image Construction ◽

Object Interaction ◽

Transmission Electron ◽

Scanning Transmission ◽

Optical Treatment ◽

Electron Microscopes ◽

Intensity Contrast

In the formation of an image each small volume element of the object is correlated to an areal element in the image. The structure or detail of the object is represented by changes in intensity from element to element, and this variation of intensity (contrast) is determined by the interaction of the electrons with the specimen, and by the optical processing of the information-carrying electrons. Both conventional and scanning transmission electron microscopes form images which may be considered in this way, but the mechanism of image construction is very different in the two cases. Although the electron-object interaction is the same, the optical treatment differs.

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