Single-use virus inactivation system for batch and continuous processing
The Cadence Virus Inactivation (VI) system is a fully automated system that provides the ability to perform low pH virus inactivation to an incoming elution stream continuously, with minimal operator involvement.
- Designed for integrated unit operation
- Fully automated for true continuous processing
- Reduced risk of operator error
- Ability to operate in batch or continuous mode for flexible facility fit
Automation of the manual operations of elution collection, titration to low pH, hold, titration to high pH, and then transfer out.
The system comprises of a control unit which attaches to one or two system specific Allegro™ single-use mixers dependent on the application. The specification of the manifolds currently supports 24 hours continuous operation.
Low pH virus inactivation has traditionally been a labor intensive task, involving a sequence of manual operations. The Cadence Virus Inactivation system takes this proven methodology and fully automates the process.
The progress toward unit operation integration and parallel continuous processing makes the adoption of an automated methodology necessary, with the added benefits of reduced operator error and more repeatable operations.Figure 1
A circular process status graphic shows system state at a glance
The software represents the latest generation of the Pall automation philosophy; such that all interactions and workflows have been carefully designed and tested to minimize operator error and allow easy interaction with the system.
The program comes with inbuilt sequences for both batch and continuous operation, which can be fully configurable to meet all process requirements. The system is supplied with an Open Platform Communications (OPC) server to allow easy connection with other units and supervisory control and data acquisition (SCADA) systems.Figure 2
Home screen of the software
Schematic of the Cadence Virus Inactivation system
Mode of OperationRecirculation Loop
The fluid flow into and out of the mixer is via the bottom of the unit, using the recirculation loop. The recirculation loop facilitates:
- Entry of externally pumped elutions into the mixer
- Addition of acid and base
- Transfer out of treated elution pool after processing
- Mixing of the elution pool during titrations and hold
- Sampling of elution pool
The gentle manner of liquid addition from the bottom of the mixer, combined with close control of the impeller by the control unit allows the transfer, titration and mixing of the elution pool without foaming and splash back – minimizing the risk of carry over between batches of elution.
Two Mixer Operation
The system mimics the traditional approach of manual low pH virus inactivation. The collection, low pH titration down, hold and high pH titration are all performed in the same mixer.
During continuous operation, when the system has reached steady state, the incoming elution flow is collected into one mixer, while the second mixer processes the collected elutions.
When mixer #2 has finished processing and has transferred out the current treated elution pool, it is then available for receiving elutions. Mixer #1 can then begin treating the next batch of elutions while the elution stream is directed to mixer #2. The diversion of the flow between mixers can be set to be switched immediately once a mixer is empty, when a certain fill level has been reached, or alternatively when connected to the continuous chromatography system at the end of the current elution after a certain minimum volume has been collected.
The valve block provides an effectively zero dead-leg valve configuration which ensures that the entire elution pool in the mixer and recirculation loop are effectively mixed and exposed to the inactivation cycle.
Single Mixer Operation
The system can operate with only one mixer attached, facilitating batch operations. A dedicated method template is included within the software to allow easy configuration.
To ensure time efficient operation, the titrations are based on a decreasing dosing volume system. An initial large dose is added to make a quick step change in pH to get close to the desired set point, subsequently medium sized doses are added until an intermediate set point is reached. To obtain the final pH set point the titration process adds small doses, mixes and checks the pH until the final set point is reached.
The use of decreasing dose methodology ensures that the risk of overshoot is minimized, while processing in a timely manner.
For both acid and base additions, the titrations are fully configurable to ensure that the process can be optimized for a particular application.
Pall can supply onsite support with a subject matter expert to ensure that configuration and integration with your process is as easy as possible.
pH graph showing steady state titrations to low pH and high pH set points
Cadence Virus Inactivation
|Dimensions main control unit
|1100 x 900 x 2005 mm without warning light
1100 x 900 x 2225 mm with
|Dimensions Allegro mixer
|964 x 654 x 1364 mm|
|Weight||350 kg (main control unit)
155 kg (Allegro mixer, full)
105 kg (Allegro mixer, empty)
|Number of mixer positions||2
(2 required for continuous operation,
1 required for batch operation)
|Maximum operating pressure||0.4
(Atmospheric pressure only in
(Main control unit feeds air to the mixers)
|Electricity supply||Single phase|
Cadence Virus Inactivation –
Single-Use (SU) System
|Hose and connectors||All tubing is silicone, with CPC
connectors internally and sanitary clamp
connectors to interface with upstream
and downstream processes
|Pressure||PendoTECH pressure transmitter|
|Recirculation pump||Insert is standard silicone tubing rated for
24 hours operation
|Transfer pump||Insert is standard silicone tubing rated for
24 hours operation
|Gamma irradiation dose||25-50 kGy|
|Tube size||1/4 in., 3/8 in., 1/2 in.|
Process Wetted Materials
|Material*||Claims & Compliances|
|Silicone||USP <88> Class VI, USP <87>, 21CFR177,
latex free, phthalate free, melamine free
|Polypropylene (PP)||USP <88> Class VI, 21CFR177, latex free,
phthalate free, melamine free
|Polysulfone (PSU)||USP <88>. Class VI, ISO 10993, USP <661>,
USP <381>, latex free, phthalate free,
|Phthalate free||USP <88> Class VI, ISO 10993, USP <661>,
latex free, melamine free
|Expiry and Lead Time|
|Lead time||Manifolds are made to order on a lead
time of 6 weeks ex-works
|Expiry||Manifolds carry a minimum shelf life of 24 months|
*All components are either ADIF or EMA/410/01 compliant
The Cadence VI system can process elutions at a rate of up to approximately 30 L/hr. The flow rate that the system can accommodate is dependent on titration behaviors, incubation time and other upstream process conditions.
To put this into context, for a typical mAb process the tables below show a guideline operating envelope for the Cadence Virus Inactivation system with 50 L Allegro single-use mixers. Please contact Pall for help with detailed capacity determination.
The manifolds are designed to be installed in less than30 minutes, and are color coded to ensure that the installation is right first time, every time. The operator is additionally lead by an onscreen installation guide. The entire process has been developed through user testing to ensure simple installation, resulting in time savings while minimizing operator error.
Cadence Virus Inactivation
|VICAD-PR-1||VI - Control system complete with two
|VICAD-LGR-50||VI - Allegro 50 L mixer VI specific|
|The Cadence VI system comprises
4 separate manifolds. A manifold to
interconnect with the upstream elution
source, the control panel manifold and
two identical mixer biocontainer manifolds.
The manifolds are supplied double
bagged and gamma irradiated
|VICAD-CT-1||VI - Manifold for the control system
(includes interconnection manifold and
control system manifold), 1 required
|VICAD-MX-50||VI - Allegro 50 L mixer biocontainer
VI specific, no pH probe, 2 required to
complete the system
|LGRMX225PH||pH probe, 2 required per system,
reusable probes. First set supplied with the control system
|639-80N||pH probe installation bellows, 2 required per system|