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Insights

Notes from the simulation lab

What we learn while simulating and scaling down bioreactors - mixing, gassing, validation and the occasional surprise.

CFD23 Oct 2026

Same reactor, same speed, eleven mixing times

In a CFD study of an Eppendorf DASGIP vessel, we released eleven tracers into the same running flow and measured mixing times anywhere between 20.3 and 23.5 seconds. This is why one mixing time per reactor is not enough to compare two reactors.

CFD23 Oct 2026

Validation first: can CFD rank stirrer positions by kLa?

In a demanding 2 L kLa comparison at 1.5 vvm and 1400 rpm, we changed only the stirrer position and compared CFD against experimentally measured kLa. Even though the values were close, the simulation ranked the configurations in the right order and found a stirrer position that performed better than the standard setup.

DREAM-bio23 Oct 2026

Introducing DREAM-bio: exploring whole bioreactor design spaces

DREAM-bio is p4b's digital bioreactor design and optimization service. Together with you we define the parameters to vary, then the simulations are generated and run semi-automatically and you get structured, comparable results across the whole design space.

CFD23 Oct 2026

We expected 100 rpm to mix fastest. It didn't.

A gas-liquid CFD study of a 2000 L single-use bioreactor similar to a Cytiva XCellerex setup showed the fastest mixing at ~80 rpm and the slowest at 100 rpm. In this design, the impeller's main job is to control how far the gas plume spreads.

Case study23 Oct 2026

Scaling down the physics, not just the volume

At the University of Stuttgart, a 3 L reactor with a p4b pDS insert was tested in a pH-shift mixing experiment followed by a CHO process. With the insert, mixing slowed from a few seconds to about 30 seconds, matching what is expected in a 2000 L XCellerex.

Scale-down18 Aug 2026

When 4 seconds become more than 30: off-the-shelf pDS inserts for the Ambr250

In one of our Ambr250 experiments, the vessel mixed in about 4 seconds without an insert and in more than 30 seconds with one of our off-the-shelf pDS inserts, approximating the mixing behavior of a 2000 L production bioreactor. Standard pDS inserts for the Ambr250 are now available off the shelf.

Events30 Apr 2026

p4b at the BioProScale Symposium

Manfred Satzer and Lena Achleitner represented p4b at the BioProScale Symposium with an industry talk and a technical presentation. The conference had a strong scientific focus and plenty of good discussions.

Case study24 Jul 2025

pDS reactors featured in a peer-reviewed article on Zika vaccine production

Our technology is featured in a peer-reviewed article by Sven Göbel and Yvonne Genzel's group at the Max Planck Institute (MPI). The 3D-printed down-scaled reactors made it possible to study, at bench scale, how viral sensitizers affect Zika vaccine production.

pDS inserts next to Ambr 250 vessels
White paper · CHO demonstration case

Large-scale conditions in a 1 L lab bioreactor

How a reactor designed by generative AI recreates the gradients of a 10,000 L scale in a 1 L vessel - and what they do to lactate and mAb titer in a CHO process. 4 pages, free.

Download the white paper
Get in touch

Let's find out how your process reacts to scale

Tell us your system and target scale - we come back with a proposal for your insert set.

Lena Achleitner
Lena AchleitnerSenior Bioprocess Engineer, Key Account Managerlena.achleitner@p4b.io