Table 3.

Reduction of three important impurities during the purification process

	RF for HCP			RF for mAb			RF for HMWP
	Batch 1	Batch 2	Batch 3	Batch 1	Batch 2	Batch 3	Batch 1	Batch 2	Batch 3
Affinity chromatography	270	266	383	–	–	–	ND	ND	ND
AIEX	5	5	6	32	15	24	1	1	1
SEC	15	13	10	5	5	2.5	18	6	5
Total RF	20 250	17 290	22 960	160	75	60	18	6	5

Results are from three different manufacturing batches. AIEX, anion exchange chromatography; HCP, host cell protein; HMWP, high molecular weight protein; ND, not determined; RF, reduction factor (calculated as amount in the load/amount in the pool): total RF is calculated by multiplication of RF values in each column; SEC, size exclusion chromatography.