Table I.

Liquid-liquid phase separation temperatures, T_ph, of a pharmaceutical IgG (P1) and the slope of PEG concentration dependency of T_ph, ${\left(\partial T_{\mathrm{ph}}/\partial c_2\right)}_{c_1}$, as a function of the protein concentration. The deviations of directly measured T_ph are calculated using T_clear – T_ph indicating the hysteresis between clouding temperature and the clearing temperature. The deviations of extrapolated T_ph are the errors of linear fitting of T_ph versus PEG concentration c₂.

IgG concentration (mg/ml)	10	30	51	96	143	188
Measured Tph (°C)	…	−3.9 ± 0.2	−3.1 ± 0.2	−2.6 ± 0.1	−3.3 ± 0.2	−3.9 ± 0.2
Extrapolated Tph (°C)	−9.2 ± 0.4	−3.9 ± 0.3	−3.4 ± 0.3	−2.8 ± 0.2	−3.2 ± 0.4	−3.8 ± 0.3
${\left(\partial T_{\mathrm{ph}}/\partial c_2\right)}_{c_1}$ (°C ml/mg)	0.70 ± 0.01	0.91 ± 0.01	1.04 ± 0.01	1.27 ± 0.01	1.72 ± 0.01	1.90 ± 0.04