Fig. 2: SAXS analysis of mAb presenting concentration scaled scattering intensities after background subtraction for T = 25 °C.
The form factor PmAb(Q) was extracted by extrapolation of concentrations ≤25 mg/ml to conc = 0. The form factor is fitted within a differential evolution algorithm and refined by a Levenberg-Marquardt fit (black line). The experimental form factor at higher Q is independent of concentration, which demonstrates that the average configuration of mAb is independent of the distance to the neighboring mAb. The inset shows the revealed SFs using \(I(Q) \sim c{S}^{{\prime} }\left(Q\right){P}_{{mAb}}(Q)\). Lines show fits using a RMSA SF54 for conc. ≤25 mg/ml and a two-Yukawa potential55 for conc.>25 mg/ml allowing for individual potential strength of the attractive and repulsive components. See SI for details about the RMSA and two-Yukawa potential and resulting SF parameters. Error bars represent standard deviation of the mean.
