Four pump architectures dominate bioprocessing today: peristaltic, positive displacement diaphragm, centrifugal, and rotary lobe. Each moves fluid through a fundamentally different mechanism. That mechanism, more than any flow rate spec on a datasheet, determines what your product looks like when it reaches the next step.
What pump types are used in bioprocessing?
Bioprocessing uses four primary pump architectures. Peristaltic pumps compress tubing to move fluid. Positive displacement diaphragm pumps use flexible diaphragms moving in chambers. Centrifugal pumps use a rotating impeller. Rotary lobe pumps use meshing lobes. Each appears in different parts of a biopharma facility for different reasons.
How do peristaltic pumps work?
A peristaltic pump squeezes flexible tubing between rollers and a track. The compressed section displaces fluid forward; as the roller releases, the tubing relaxes and refills behind it. Repeat. The product never touches the pump body, only the tubing.
This is why peristaltic pumps dominate single-use bioprocessing: the tubing is the wetted path, and a fresh tubing assembly per batch eliminates cleaning entirely. They are cheap to deploy, sanitary by construction, and forgiving on operators.
The tradeoff is the mechanism itself. Compressing tubing thousands of times per run generates shear stress on the fluid and particle generation from tubing fatigue. For monoclonal antibodies and other robust biologics, that is acceptable. For shear-sensitive products including lipid nanoparticles, enveloped viral vectors, and antibody-drug conjugates, it is a documented cause of measurable yield loss. Capsid stability varies by serotype; AAV, for example, is comparatively shear-resistant.
How do positive displacement diaphragm pumps work?
A positive displacement diaphragm pump uses one or more flexible diaphragms to move fluid through a sealed chamber. As the diaphragm flexes outward, it draws fluid in through an inlet check valve. As it flexes back, it pushes fluid out through an outlet check valve. The diaphragm never compresses the fluid against a rigid wall, and the chamber geometry is engineered for predictable flow.
For biopharma, the advantages are specific. Low shear because the fluid is not squeezed or impeller-contacted. Low pulsation when multiple diaphragms are phased to cancel each other's pressure peaks (odd-number designs cancel harmonics better than even-number designs). Wide viscosity tolerance because gravity-flooded suction designs do not cavitate at high viscosity the way other architectures do.
Our PIXER pump family is a single-use positive displacement diaphragm design available in three, five, and seven-diaphragm configurations, built specifically for fragile modalities and for the recirculation loop inside a TFF system.
How do centrifugal pumps work?
A centrifugal pump uses a rotating impeller inside a volute (a spiral chamber) to accelerate fluid outward. The kinetic energy converts to pressure as the fluid leaves the impeller. Centrifugal pumps move high volumes at moderate pressure with simple, robust mechanics.
They are the workhorse of large-volume transfer, CIP loops, and water systems. They are also a poor choice for sensitive products. The impeller makes direct, repeated mechanical contact with everything passing through it. For viscous fluids, the impeller stalls. For shear-sensitive biologics, the impeller does the damage that peristaltic compression does in a different way.
How do rotary lobe pumps work?
A rotary lobe pump uses two meshing rotors (lobes) that turn in opposite directions inside a chamber. As the lobes rotate, they create cavities that draw fluid in on one side and push it out on the other. The rotors do not touch each other; they are timed by external gears.
Lobe pumps handle viscous and shear-sensitive fluids better than centrifugal, with lower pulsation than single-diaphragm designs. They appear in fermentation harvest, viscous transfer, and continuous bioprocessing. Sanitary models with USP Class VI elastomers and ASME BPE chemistry are widely available. They are not single-use; they require cleaning between batches.
Which pump type belongs where?
The shape of the decision changes with the application. A rough map:
| Pump type | Shear source | Pulsation | Viscosity ceiling | Best for | Avoid for |
|---|---|---|---|---|---|
| Peristaltic | Tubing compression | High (roller frequency) | Limited at higher viscosity | Single-use transfer, mAb processing | LNPs, enveloped viral vectors, ADCs, cell therapy |
| Diaphragm (positive displacement) | Low; chamber geometry dominant | Low (multi-diaphragm) | ~1,000 cP (quaternary); higher for radial configurations | Fragile modalities, TFF recirculation, viscous transfer | Very high-volume low-viscosity transfer |
| Centrifugal | Impeller contact | Very low (continuous) | Low (cavitation at viscosity) | Water, buffer, CIP, large transfer | Shear-sensitive product, viscous fluids |
| Rotary lobe | Mesh-edge shear | Moderate | High | Viscous transfer, fermentation harvest, continuous | Critical aseptic single-use applications |
What matters more than the flow rate?
The mechanism. Every pump datasheet leads with flow rate and pressure capacity. Both matter for sizing the equipment. Neither tells you what the pump is doing to your product on the way through.
The often-overlooked insight: Two pumps rated for the same flow rate and the same pressure can cause radically different damage to the same product. Peristaltic compression generates particles even when flow rates are conservative. Centrifugal impellers shear LNPs even at moderate RPM. Diaphragm pumps with gravity-flooded suction extend further up the viscosity curve than centrifugal designs, which cavitate before the diaphragm geometry would. Specify on the mechanism, not the spec sheet.
Where to read next
If you are designing or evaluating a process where pump architecture matters (TFF, viral vectors, ADCs, cell therapy, anything with shear sensitivity), the deeper articles below cover the specific mechanisms.
How Diaphragm Pumps Work
Deep dive into positive displacement architecture. Coming soon.
The Peristaltic Problem
Compression, particle generation, and protein loss. Coming soon.
TFF for Viral Vectors
Why pump architecture matters more than membrane selection for fragile modalities. Read →
Is It Shear Damage or Pump Damage?
How to diagnose the difference and where to look first. Read →
The mechanism behind PIXER. Why positive displacement matters for fragile modalities, and where diaphragm pumps fit in the broader pump landscape.
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