Performance of an acoustic settler versus a hollow fiber-based ATF technology for influenza virus production in perfusion.

Process intensification and integration is crucial regarding an ever increasing pressure on manufacturing costs and capacities in biologics manufacturing. For virus production in perfusion mode, membrane-based alternating tangential flow filtration (ATF) and acoustic settler are the commonly described cell retention technologies. While acoustic settlers allow for continuous influenza virus harvesting, the use of commercially available membranes for ATF systems typically results in the accumulation of virus particles in the bioreactor vessel.

Viscosity sensor utilizing a piezoelectric thickness shear sandwich resonator.

This paper describes a novel quartz crystal sensor for measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two piano-convex AT-cut quartz crystals vibrating in a thickness-shear mode with the liquid sample in between. This special set-up allows suppression of disturbing resonances in the liquid layer.

Comparison of fluidized bed and ultrasonic cell-retention systems for high cell density mammalian cell culture.

Economically viable biopharmaceutical production is to a high degree dependent on high product yields and stable fermentation systems that are easy to handle. In the current study we have compared two different fermentation systems for the production of recombinant protein from CHO cells. Both systems are fully scaleable and can be used for industrial high cell density bioprocesses.

Use of an ultrasound cell retention system for the size fractionation of somatic embryos of woody species.

 The potential of ultrasonic standing waves for trapping suspended particles was utilized successfully for differential size fractionation of plant somatic embryos. In a flow-through resonator equipped with a 200-kHz piezoceramic transducer, embryos of different sizes corresponding to different developmental stages could be retained by varying the electric power input and flow speed. The system was initially established for carrot (Daucus carota) somatic embryos and subsequently adapted for the larger-sized embryos of the woody species cork oak (Quercus suber), grapevine (Vitis Berlandieri × rupestris) and cherry (Prunus incisa × serrula).

Batch and semicontinuous aggregation and sedimentation of hybridoma cells by acoustic resonance fields.

Ultrasound was used to enhance the sedimentation of hybridoma cells from medium in a 75 mL resonator chamber. Forces in the acoustic standing waves aggregated the cells, and the aggregates were then rapidly sedimented by gravity. Cell separation increased with acoustic treatment time and cell concentration.