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shear stress investigations of the magnetically levitated single-use centrifugal pump puralev 600SU using the protein shear stress model for lysozyme_cover

Shear Stress Investigations of the PuraLev® 600SU Using the Protein Shear Stress Model for Lysozyme

  • Bioprocessing
  • Pump Comparison
  • 4-Piston Diaphragm Pump
  • Shear Stress
  • Protein Activity

In comparison to a Levitronix® pump, a 4-Piston Diaphragm Pump consists of multiple valves that restrict fluid motion to the desired direction. Valve interaction can lead to shear stress, which can result in reduced protein quality.

Test conditions
The Levitronix® PuraLev® 600SU and a 4-Piston Diaphragm Pump of corresponding hydraulic power were evaluated for their generation of shear stress and its effect on protein activity. A fixed volume of lysozyme was pumped in two identical closed-loop configurations. The flow rate of each pump was set to 10 and 20 lpm, and backpressures of 1.5, 2, 2.5 bar, respectively. Protein activity and size were measured at selected times and compared.

Protein activity did not change significantly for the PuraLev® 600SU during the entire test. The fluctuations are within an acceptable margin of error. In contrast, the 4‐piston diaphragm pump showed a significant decrease in protein activity in all tests.


Protein activity and size at 10 lpm and 1.5 bar

Author Cedric Schirmer, Dieter Eibl
Company ZHAW
Document Number -
Pages 43