The goal of this service is to determine the relative amount (percentage) of
individual protein species in a mixture. The service is also used in
quantitation of any minor impurity proteins (>0.01% of total), including low
level degradation products of the major protein in a biologic product.
The low-level protein impurities in a therapeutic protein
product often include proteins released from host cells, proteins from cell
culture media, and proteins from bacteria or virus that has infected of a cell
culture (such as mycoplasma). They may also include degradation products such as
cleaved protein forms, truncated protein forms, as well as oxidation and
deamidation products.
The quantitation depends on a high resolution separation of a protein mixture
by SDS-PAGE. After coomassie and/or silver staining, each gel band is measured
by a densitometer to determine the percentage of the gel band in the
mixture.
We can also combine the protein quantitation service with our protein
identification service to report the identity and percentage of each protein in
a mixture.
