Fractogel® EMD TA is an affinity resin designed
specifically for the purification of antibodies and can be utilized
instead of ion exchangers or in combination with other methods. The
high efficiency of the thiophilic adsorption chromatography is based
on the specific interaction of a covalently bound sulfur containing
ligand immobilized on a chromatographic support with its counterpart.
The mechanism is based on a salt promoted adsorption of proteins to
a sulfone and thioether containing heteroaliphatic ligand. The binding
of the protein takes place mainly via accessible tryptophane and/or
phenylalanine residues. Corresponding motifs can be observed within
conserved regions of various antibodies. Unlike Protein A, antibodies
can be eluted at physiological pH conditions. Albumins are not adsorbed
on thiophilic media, which often simplifies the effective separation
of antibodies.
Antibodies of the IgM sub-class and recombinant antibodies produced in E. coli can also be
purified.
Getting Started Now (Practical hints)
The best results for antibody isolations are obtained at ammonium
sulfate concentrations between 0.8M and 1.5M. The elution can be achieved
by applying a decreasing gradient of the concentration of ammonium
sulphate. Although in affinity chromatograhy a step wise gradient
for elution is often preferred, sometimes gently decreasing salt gradients
can provide better separations. |
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