Table 2.

Methods of assessing the stability of antibody therapeutics. *Aggregation and concurrent loss or decrease in activity/function are the most common sources of instability during aerosolization or upon contact with collection surfaces

Sources of Instability	Assay/Test Methods
Primary Structure	Quantitative – Mass Spectrometry57 Qualitative – Western Blot58,59
Secondary Structure	Nuclear Magnetic Resonance60,61
Tertiary Structure	Circular Dichroism54 Optical Rotatory Dispersion
*Aggregation	Gel Permeation Chromatography55 Gel Electrophoresis62,63 Western Blot58,59
*Activity/Function	Antigen Binding56 Neutralization (replicating antigens)