Table 1.

Protein properties and diffusion constants using the Stokes-Einstein equation and FCS analysis (Eq. 1)

Protein	Mol mass, kDa	rh, nm	pI	Diffusion constants of proteins (10−10 m2/s)
				Stokes–Einstein estimate	Native in PBS (FCS analysis)	Released in PBS (FCS analysis)	Apparent in gel (Eq. 2)	Pristine in gel (FCS analysis)
Lysozyme	14.3	1.9	11.4	1.15	0.97 ± 0.18	0.96 ± 0.24	0.50 ± 0.02	0.71 ± 0.05
Trypsin inhibitor	20.1	2.4	4.6	0.91	0.74 ± 0.14	0.72 ± 0.18	0.32 ± 0.01	0.61 ± 0.04
BSA	66.0	3.6	5.3	0.61	0.53 ± 0.10	0.51 ± 0.12	0.24 ± 0.02	0.41 ± 0.06
IgG	≈150.0	5.3	≈7.2	0.40	0.38 ± 0.08	0.40 ± 0.09	0.07 ± 0.01	0.28 ± 0.02

Diffusion constants inside the hydrogel were estimated using Eq. 2 (apparent) and Eq. 1 (pristine). SD values were calculated using error propagation (n = 4 or n = 8).