4. Discussion
4.1. Characterization of Racotumomab Mab by mass spectrometry
The mass spectrum of Fig. 1(A–D) provides valuable information about the molecular species present.
The results agree with those obtained by polyacrylamide gel electrophoresis in the presence of SDS, which shows a major band at around 150 kDa in all batches analyzed (Fig. 1(E–F)). We also determined the molecular weightof the heavy and light chains, which correspond to those obtainedin polyacrylamide gel electrophoresis (Figs. 2 and 3).One common posttranslational modification observed in Mabsis a cyclized N-terminal glutamine [20–23] when either the heavy