. 2023 Oct 31;9(11):e21001. doi: 10.1016/j.heliyon.2023.e21001

Table 5.

Protein L ligand leakage, host cell proteins and endotoxin levels determined by commercial kits after two-step purification.

Purification Step	Fraction	Protein L Concentration (ng/mL)	Accepted Range
First Step (AC)	Load	–	Below 6.0 ng/mL
First Step (AC)	Elution	5.36
Second Step (CEX)	Elution	3.76
Purification Step	Fraction	HCP Concentration (ng/mL)
First Step (AC)	Load	1.67 x 10⁶	Below 100 ng/mL
First Step (AC)	Elution	661
Second Step (CEX)	Elution	16.8
Purification Step	Fraction	Endotoxin Concentration (EU/mL)
First Step (AC)	Load	1788	Below 0.5 EU/mL
First Step (AC)	Elution	0.065
Second Step (CEX)	Elution	0.031