Bio-Rad Foresight™ Chromatography Columns, Prepacked - Manual (Page 31)

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Section 4
Application Example
4.1 IgG isotherm on cPrime™
Chromatographic Media
Introduction
Many different isotherm models have been proposed for
the adsorption of proteins from a liquid solution onto a
chromatography resin surface. The Langmuir model is
widely used due to its ease of interpretation and its general
agreement with experimental data. The Langmuir model is
expressed by the following equation:
Where q (mg/ml) and C (mg/ml) represent the adsorbed
and liquid phase concentrations at equilibrium,
respectively. q
m
is the saturation capacity (mg/ml) and K
the isotherm equilibrium constant (mg/ml), representing
the affinity of the solute for the binding surface. q
m
and K
are the isotherm parameters, which can be estimated by
fitting the Langmuir model to isotherm data.
This study used a Foresight™ chromatography media
filter plate to determine isotherm data of a model molecule
(human IgG) and a mixed-mode resin. The isotherm data
were obtained using a ladder of initial hIgG concentrations
and a fixed phase ratio. The isotherm data were fitted with
the Langmuir isotherm model to determine the saturation
capacity and the association constant.
KC
q
+
=
1
KC q
m