64
afc
Affinity
chromatography
TOYOPEARL affinity resins for process scale
chromatography
There aremany customdesignedaffinity ligands available to
the chromatographer. TOYOPEARL affinity chromatography
resins are
functionalized with chemically active groups or
group-specific ligands. Resins with activated functional
groups are ready to directly couple a protein or other ligand.
Resins with reactive groups require carbodiimide coupling
or reductive amination to achieve a stable covalent linkage.
AFC – how does it work
In affinity chromatography, the target protein is specifi-
cally and reversibly bound by a complementary ligand.
The sample is applied under conditions that favor specific
binding to the ligand. Unboundmaterial is washed out of the
column, and bound target protein is recovered by changing
conditions to those favoring elution. Elution is performed
specifically, using a competitive ligand, or nonspecifically,
by changing, for example, pH, ionic strength, or polarity.
The target protein is usually eluted in a purified and concen-
trated form.
MECHANICAL & CHEMICAL STABILITY
TOYOPEARL resins remain dimensionally stable within
wide extremes of pH and ionic strength. Moreover, the
semi-rigid TOYOPEARL particles do not distort under flow
rates that generate up to 3 bar pressure. These
proper-
ties of the resins combined with the narrow particle size
distributions result in superior pressure-flow characteris-
tics for the packed TOYOPEARL bed. Linear velocities of
300 - 500 cm/h generate
a pressure of between 1 and 2 bar
in a 20 cm length bed. Achievement of high linear veloci-
ties at relatively low pressure enables high throughput
production scale chromato-graphy using equipment
with moderate pressure limitations. Sanitization
or cleaning may be conducted with up to 0.5 mol/L
NaOH or 0.5mol/L HCI depending upon the ligand. In affinity
chromatography, in particular, the choice of cleaning agent
will be largely dependent upon the chemical stability of the
ligand, rather than that of the base resin.
Table I
Activated
Reactive
Group
resin
resin
specific
AF-Tresyl
AF-Amino
AF-Blue HC
AF-Epoxy
AF-Carboxy
AF-Red
AF-Formyl
AF-Chelate
AF-Heparin HC
features
Benefits
Active, reactive and group specific resins
Broad range of applications
Standard 100 nm pore size
High capacity for large biopolymers
Porous, hydrophilic polymer matrix
Suitable for laboratory and process scale purifications
High mechanical stability
Constant bed volume over a wide range of buffer composition
