Optimization of the Imaged cIEF Method for Monitoring the Charge Heterogeneity of Antibody-Maytansine Conjugate

Table 4

Comparison of charge profiles of studied naked antibody and its corresponding ADC, including isoform number, pI range, ΔpI, and pI and % area of major species.

	Isoform number	pI range	ΔpI	pI and % area of major species
Naked antibody	2	8.9–9.0	0.1	Peak 1: pI 8.9 : 36%, Peak 2: pI 9.0 : 64%
Maytansinoid-antibody	12	7.5–9	1.5	Peak 1: pI 8.4 : 11%, Peak 2: pI 8.5 : 15%, Peak 3: pI 8.6 : 13%, Peak 3: pI 8.7 : 11%, Peak 4: pI 8.8 : 7%, Peak 5: pI 8.9 : 4%, Peak 6: pI 9.0 : 1.7%