Facts
In comparison to a Levitronix^® pump, peristaltic pumps generate flow through tube compression along a pump casing. Tube compression can generate shear stress, which results in reduced cell viability.

Test conditions
One Levitronix^® and two peristaltic pumps’ shear stress generation were compared by observing their effect on respective cell viabilities. 3.4 liters of CHO cells were introduced and pumped in three identical closed-loop configurations. The flow rate of each pump was set to 3.4 lpm and different backpressures for a period of over 400 minutes. The cell viability was measured at selected times and compared.

Results
The cell viability with the Levitronix^® pump system was consistently above 95%. The peristaltic pumps reached cell viabilities of 70% and 28%, respectively. Similar results have been recorded at four different pressure levels up to 0.5 bar.

Time dependent viability of the cell suspension pumped with 3.4Lmin without back pressure