DNA FROM CLARIFIED, LARGE-SCALE, FED-BATCH, MAMMALIAN-CELL CULTURE ISOF PREDOMINANTLY LOW-MOLECULAR-WEIGHT

The molecular weight of DNA from a large-scale, fed-batch, mammalian c ell culture vessel has been evaluated as process material passes throu gh the initial stages of a purification scheme for monoclonal antibodi es. High molecular weight DNA was substantially cleared from the broth after passage through a disc stack centrifuge and the remaining low m olecular weight DNA was largely unaffected by passage through a series of depth filters and a sterilising grade membrane. Removal of high mo lecular weight DNA was shown to be coupled with clarification of the p rocess stream. The DNA from cell culture supernatant showed a pattern of internucleosomal cleavage of chromatin when fractionated by electro phoresis but the presence of both necrotic and apoptotic cells through out the fermentation meant that the origin of the fragmented DNA could not be unequivocally determined.