| abstract |
A method for preparing an active immunoconjugate, wherein said immunoconjugate is deamidated into one or more moieties, in which deamidation results in an inhibition of the potency of said immunoconjugate, and wherein said immunoconjugate is composed of two polypeptide chains. joined by a disulfide bond, the method comprising refolding said immunoconjugate in a semi-continuous refolding process in a refolding buffer having a pH of 9.5 or less, and purifying the refolded immunoconjugate using a two cycle elution in an exchange column ionic, in which the column is separated between a first elution and a second elution with a separation buffer comprising ethanolamine, arginine, ethylenediaminetetraacetic acid (EDTA), urea and dithiothreitol (DTT). |