Figure 3. Overlay of IEX-HPLC chromatograms of mAb C samples stored for one month (A) and three months (B) at -80°C, 2–8°C, 25°C and 40°C. Evolution during stability studies of relative amount of deamidation at HCAsn33 (N33, blue trace) and mAb B potency (red trace) (C). The bar graph represents the relative area of acidic variants after one month at 40°C in six different formulations (D). Deamidation at Asn33 in rhesus monkey serum stability studies (E): TIC of the doubly charged ion of peptide 25–39 at day 0, 7, 14 and 21: The peak at ~33–34 min is the early eluting non deamidated parent peptide (Asn33), the two peaks eluting at 34–36 and 35–37 min are the deamidated product peptides (iso-Asp33 and Asp33, respectively). At all-time points the ratio of deamidated product peptides IsoAsp/Asp is the same, ~1:5 throughout the whole experiment. Titration of mAb C in rhesus monkeys serum by an anti-kappa light chain (PK curve) and antigen ligand-capture (Antigen curve) ELISAs after second injection (F).