Biomedical Engineering Reference
In-Depth Information
typical for protein A-based chromatography media. As a result of differences
in scale, chromatography systems, and UV detectors, the relative eluate vol-
umes measured in CV were slightly different in the XK and ReadyToProcess
runs. Each of the five eluates from the XK runs had volumes corresponding
to 1.7 CV, while the five eluates from the ReadyToProcess runs had volumes
corresponding to 2.0 CV. Therefore, the sample volumes in the subsequent
Capto Q and Capto adhere steps were smaller for the XK runs compared to
the ReadyToProcess runs. This difference becomes apparent when compar-
ing the XK and the ReadyToProcess chromatograms from the Capto Q and
Capto adhere runs.
The mAb-containing flowthrough and part of the wash were collected.
Again, the comparable performance of the XK and ReadyToProcess columns
was confirmed by the analytical results. The Capto Q step was characterized
by high yield, reduction of HCP, and some reduction of leached ligand and
dimer/aggregates. Capto adhere step The mAb-containing flow through and
all of the wash were collected. Again, the comparable performance of the XK
and ReadyToProcess columns was confirmed by the analytical results. The
Capto adhere step had a high yield and efficiently reduced the amount of
dimers and aggregates in this study. With this particular mAb, it was neces-
sary to run the column at low pH (pH 5.0) and high salt (0.4 M NaCl) condi-
tions. At these conditions, the HCP removal is limited. Typically, when the
mAb allows running at higher pH and lower salt conditions, Capto adhere
also removes HCPs.
The performance of ReadyToProcess columns is comparable with
established column formats as has been demonstrated in a three-step
mAb purification process run in parallel at two different scales: small-
scale XK columns and large-scale, prepacked ReadyToProcess columns.
The ReadyToProcess columns behave similarly to the XK columns in all
aspects studied, demonstrating that the purification process is directly
scalable between XK and ReadyToProcess. Multiple cycles (five) have been
performed on RTP MabSelect SuRe 2.5 without any detectable changes in
column performance.
Smaller disposable columns are available from several sources including
Bio-Rad (
www.bio-rad.com
) and Corning (
www.corning.com
). There is still
an unmet need for inexpensive large disposable columns.
A disadvantage in using resin columns is the large footprint required
in their use; compared to this, membrane chromatography employs thin,
synthetic, porous membranes that are generally multilayered in a small
cartridge, significantly reducing the footprint of the operation. Membranes
have the same functional chemical groups to corresponding resins, but
they do not need packing, checking, cleaning, refilling, or routine main-
tenance, and fouled or exhausted modules can be replaced with new ones
with minimal process downtime. Sartorius offers a large choice in these
membranes.
