Comparability of a Three-Dimensional Structure in Biopharmaceuticals Using Spectroscopic Methods

Table 4

Specificity and accuracy of thiol analysis. Controls are specified for DTNB method and DLM method.

Protein	Condition	Cys/Protein molar ratio
		DTNB	DLM
Somatropin	Denaturing/reducing	3.98 ± 0.31	NT
HSA	Native	NT	1.01 ± 0.17
Glatiramer acetate		0.001 ± 0.007	0.045^a
Placebo Rituximab		0.0005 ± 0.001	0.0004^a
Placebo Etanercept		0.0005 ± 0.001	0.0024^a
Protein marker		NT	0.0005^a

NT: not tested.
^aSD value is less than 1 × 10⁻⁵.