ThermoFisherScientific_Jan2021_ADeepDiveInto - 20

Best Practices for Evaluating a Perfusion Medium
Consider the continuous perfusion operated at two
steady states in Figure 1 on the following page. For the
first 19 days, the culture operation is run using a recipe
generated from previous studies and achieves an excessively high percent of cell viability. Running with an
unnecessarily high cell viability doesn't properly utilize
the medium. For example, nutrients are less utilized
before they are removed in the spent medium, thus
hurting the process efficiency. From day 20 onward, the
continuous perfusion run is adjusted to actively target
a slightly lower viability at about 95%. This change has
a notable impact on the viable cell density (VCD) at
steady state and the productivity of the process. When
the process works at 95% viability, the medium is better
utilized by the higher VCD leading to a more efficient
process, and achieving a steady-state cell density of
about 120 x 10⁶ viable cells/mL and a cell-specific
productivity (Qp) of about 30 pg/cell/day
(approximately 1.7 g/L/day harvest titer).

Clear operating goals and
mechanisms to achieve them
should be planned out so that
the medium tested can be put
on a level playing field that is
meaningful for the process goals.

160

100

140

95

120

90

100

85

VCD

80

80

Qp

60

% Viability

40
20
0
0

75
70

Cell viability (%)

Viable cell density (x 10 6/mL)
Qp (pg/cell/day)

How a perfusion operation is carried out has a significant impact on the results. Clear operating goals and
mechanisms to achieve them should be planned out
so that the medium tested can be put on a level
playing field that is meaningful for the process goals
and effectively challenges what is being evaluated.

65
5

10

15

20

25

30

35

40

60

Days

Figure 1. Continuous perfusion at steady state. 1 vessel volume per day (VVD) continuous perfusion using Gibco™ High-Intensity Perfusion
(HIP) CHO Medium. At day 19, the operation was changed to better utilize the medium, resulting in a new steady state targeting a lower
percent cell viability. New targets were reached around day 26.
20 | GENengnews.com


https://www.genengnews.com https://www.genengnews.com

ThermoFisherScientific_Jan2021_ADeepDiveInto

Table of Contents for the Digital Edition of ThermoFisherScientific_Jan2021_ADeepDiveInto

Contents
ThermoFisherScientific_Jan2021_ADeepDiveInto - 1
ThermoFisherScientific_Jan2021_ADeepDiveInto - 2
ThermoFisherScientific_Jan2021_ADeepDiveInto - Contents
ThermoFisherScientific_Jan2021_ADeepDiveInto - 4
ThermoFisherScientific_Jan2021_ADeepDiveInto - 5
ThermoFisherScientific_Jan2021_ADeepDiveInto - 6
ThermoFisherScientific_Jan2021_ADeepDiveInto - 7
ThermoFisherScientific_Jan2021_ADeepDiveInto - 8
ThermoFisherScientific_Jan2021_ADeepDiveInto - 9
ThermoFisherScientific_Jan2021_ADeepDiveInto - 10
ThermoFisherScientific_Jan2021_ADeepDiveInto - 11
ThermoFisherScientific_Jan2021_ADeepDiveInto - 12
ThermoFisherScientific_Jan2021_ADeepDiveInto - 13
ThermoFisherScientific_Jan2021_ADeepDiveInto - 14
ThermoFisherScientific_Jan2021_ADeepDiveInto - 15
ThermoFisherScientific_Jan2021_ADeepDiveInto - 16
ThermoFisherScientific_Jan2021_ADeepDiveInto - 17
ThermoFisherScientific_Jan2021_ADeepDiveInto - 18
ThermoFisherScientific_Jan2021_ADeepDiveInto - 19
ThermoFisherScientific_Jan2021_ADeepDiveInto - 20
ThermoFisherScientific_Jan2021_ADeepDiveInto - 21
ThermoFisherScientific_Jan2021_ADeepDiveInto - 22
ThermoFisherScientific_Jan2021_ADeepDiveInto - 23
ThermoFisherScientific_Jan2021_ADeepDiveInto - 24
ThermoFisherScientific_Jan2021_ADeepDiveInto - 25
ThermoFisherScientific_Jan2021_ADeepDiveInto - 26
ThermoFisherScientific_Jan2021_ADeepDiveInto - 27
ThermoFisherScientific_Jan2021_ADeepDiveInto - 28
ThermoFisherScientific_Jan2021_ADeepDiveInto - 29
ThermoFisherScientific_Jan2021_ADeepDiveInto - 30
ThermoFisherScientific_Jan2021_ADeepDiveInto - 31
ThermoFisherScientific_Jan2021_ADeepDiveInto - 32
ThermoFisherScientific_Jan2021_ADeepDiveInto - 33
https://www.nxtbookmedia.com