Fig. 5.

Standard curves for determination of apparent viscosity. A. Reference curves for how the average R₂ rates of the three probe proteins (shown in Fig. 4) change with increasing microscopic viscosity (corresponding to pure η^int in Eq. (2)). Colour coding is as in Fig. 1, and error bars are the translated error from signal to noise in signal intensity determination. The slope δR₂/δη is directly linked to the size of the protein, as highlighted in the correlation plot in B.