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Rheology of clustering protein solutions



Vishnu Dharmaraj, P. Douglas Godfrin, Yun Liu, Steven Hudson


High viscosity is a major challenge with protein therapeutics at extremely high concentration. Understanding the relationship between the concentration of a protein solution and its viscosity as a function of shear rate and temperature is therefore essential. Here, with measurements from a micro-capillary rheometer (using only several microliters of solution), we report the viscosity of lysozyme protein solution over a range of parameter space: lysozyme solution concentrations ranging from 12 % mass fraction to 40 % mass fraction, shear rates ranging from 100 /s to 400,000 /s and temperatures ranging from 5 °C to 50 °C. Lysozyme is a model protein that has short range attractive and long range repulsive interactions. As expected, with either increasing concentration or decreasing temperature, the viscosity increased dramatically across all shear rates. Most of the solutions exhibited Newtonian behavior. However, at the highest concentration (40% mass fraction), shear thinning was exhibited at shear rates above approximately 10,000 /s. These measurements probe the dynamics of reversible association in protein clusters and by testing reversibility can distinguish aspects of the dynamics of equilibrium and non-equilibrium structures.


rheology, protein solutions, biomanufacturing, viscosity, clustering, cluster dynamics


Dharmaraj, V. , Godfrin, P. , Liu, Y. and Hudson, S. (2016), Rheology of clustering protein solutions, Biomicrofluidics, [online],, (Accessed July 18, 2024)


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Created July 4, 2016, Updated October 12, 2021