4.2. Analysis of molecule charge
Cation-exchange chromatography has been introduced to measure charge heterogeneity, in particular caused by lysine variants,more than 15 years ago [29] and now is widely accepted in pharmaceutical analysis. When performing the analysis of micro-heterogeneity of load HPLC-WCX (Fig. 5) we can see that in Racotumomab-ST41L, there are three clusters of four bands as explained above.