Affinity Chromatography - Department of Molecular and Cellular ...

Removal of lipoproteins
Lipoproteins and other lipid material can rapidly clog chromatography columns and it is
advisable to remove them before beginning purification. Precipitation agents such as
dextran sulphate and polyvinylpyrrolidine, described under Fractional precipitation, are
recommended to remove high levels of lipoproteins from samples such as ascitic fluid.
Centrifuge samples to avoid the risk of non-specific binding of the target molecule to a filter.
Samples such as serum can be filtered through glass wool to remove remaining lipids.
Removal of phenol red
Phenol red is frequently used at laboratory scale as a pH indicator in cell culture. Although
not directly interfering with purification, phenol red may bind to certain purification media
and should be removed as early as possible to avoid the risk of contamination. It is known
to bind to anion exchange media at pH > 7.
Use a desalting column to simultaneously remove phenol red (a low molecular weight
molecule) and transfer sample to the correct buffer conditions for further purification, as
described under Buffer exchange and desalting.
Removal of low molecular weight contaminants
If samples contain a high level of low molecular weight contaminants, use a desalting
column before the first chromatographic purification step, as described under Buffer
exchange and desalting.
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