Fig. 2.

Potential mAb variants

An IgG antibody schematic is shown, with some potential structural variations resulting from post-translational modifications indicated by symbols. Each symbol is noted in the key with a list of variations. The number of variation sites in each half-antibody × the number of possible variations at each site is in parenthesis. Not all possible variants are described. For example, there are fucosylation variants in glycosylation that were not counted. If one assumes that these variants are independent and if combinations are considered, each half-antibody has 2 × 6 × 4 × 4 × 5 × 5 × 2 = 9600 possible states. If one assumes that both halves of the antibody are independent, there are 9600² ≈ 10⁸ possible states. Reprinted from Kozlowski S, Swann P. Current and future issues in the manufacturing and development of monoclonal antibodies. Adv Drug Deliv Rev 2006;58(5–6):707–22, [37], ©2006, with permission from Elsevier.