ThermoFisherScientific_Jan2021_ADeepDiveInto - 6

Perfusion: An Overview
retaining cells, resulting in some cell removal (often
referred to as bleed) in the spent medium. Retention mechanisms are selected based on the process
needs; settling methods may have reduced costs
and lower risk of system fouling, whereas filtration
methods that allow 0.2 µm filters provide fully clarified
permeate that can immediately be linked to further
downstream processing.

Advantages of Perfusion
There are many advantages to using perfusion,
including flexibility, low cost, improved quality,
and speed.

Flexibility
High-quality production on demand-
High-quality production is achieved with a smaller
footprint than with a traditional fed-batch process
(both upstream and downstream). When perfusion
is paired with single-use technology, it becomes
easier to implement the workflow to produce what
is needed when it is needed. Users can easily switch
between product runs using the same equipment.
Scalable commitment-Perfusion allows the end
user to start with a smaller commitment and, if justified, expand quickly allowing for lower capital risk on
investment.
Easier technology transfer-Meeting technology
transfer needs and replicating workflows is easier
with a physically smaller process that has potentially
fewer steps and less scale-up compared to fed-batch
methods.

Low Cost
Simplified logistics-Smaller equipment leads to a
smaller process footprint, including capital expenditure, utilities, facility build, and cost of goods.
Scalable commitment-Faster and easier facility
builds allow for investing and expanding production
as needed.
6 | GENengnews.com

Comparison of Cell Retention Methods
The two methods for suspension cell culture
retention, settling and filtration, have different
advantages and disadvantages that need to
be considered.

Settling methods
Examples:
*	 Passive
*	 Acoustic
*	 Centrifugation
Advantages:
*	 Potentially lower cost
*	 Potentially lower risk of system fouling
Disadvantages:
*	 Imperfect efficiency-some cells will be lost
in spent medium
*	 Can be difficult to hit specific operation
scales
*	 Passive settling may take too long and
impact cell culture performance

Filtration methods
Examples:
*	 Tangential flow filtration (TFF)
*	 Alternating tangential flow filtration (ATF)
Advantages:
*	 Scalable
*	 Potential for permeate to be directly linked
to downstream processing
*	 Perfect cell retention allows for full control of
cell bleeding depending on process needs
Disadvantages:
*	 May require higher cost than comparable
settling methods
*	 May increase risk of fouling
https://www.genengnews.com https://www.genengnews.com
ThermoFisherScientific_Jan2021_ADeepDiveInto

Table of Contents for the Digital Edition of ThermoFisherScientific_Jan2021_ADeepDiveInto
