Table 3.

Analytical methods for evaluating the protein conformation

Spectroscopy methods	Principle	Detection	Properties	Proteins & peptides	Reference
Far CD, Near CD, Spectroscopy	Aromatic amino acid environment, Peptide bond	Secondary structure, Tertiary structure, Quaternary structure	Fairly expensive, Liquid sample	IgG, Lysozyme, Etanercept, PTH, Anthrax vaccine	Vermeer et al. (2000), Schüle et al. (2007), Hawe et al. (2009), Sahin et al. (2010), Emami et al. (2018a, b), Jovanovic et al. (2006), Nuchuchua et al. (2014), Kim et al. (2014), Poursina et al. (2015), Wang et al. (2012)
FTIR	Peptide bond structure	Secondary structure	Cheap solid and liquid sample	IgG, Lysozyme, Etanercept, BSA, Anthrax vaccine	Schüle et al. (2007), Hawe et al. (2009), Awotwe-Otoo et al. (2015), Jovanovic et al. (2008a, b), Kim et al. (2014), Kim et al. (2016a, b), Imamura et al. (2003), Wang et al. (2012)
Fluorescence, Spectroscopy (Intrinsic & Extrinsic)	Aromatic amino acid environment	Tertiary structure, Quaternary structure	Liquid sample	IgG, PTH, Lysozyme	Hawe et al. (2009), Sahin et al. (2010), Emami et al. (2018a, b), Poursina et al. (2015), Jovanovic et al. (2006)
UV absorbance spectroscopy	Aromatic amino acid environment	Tertiary structure	Cheap liquid sample	IgG	Emami et al. (2018a, b)

CD circular dichroism, FTIR fourier transforms infrared, BSA bovine serum albumin