Figure 7
Comparison of radiation damage in coflow versus conventional analysis. The effect of X-ray flux on RNase A scattering in conventional (a) and coflow (b) sample environments. In the conventional measurement RNase A formed aggregates, as displayed by the large increase in scattered intensity at q < 0.025 Å−1 in (a). In coflow, aggregation did not occur. A variety of parameters, including the statistical similarity of curves (calculated with DATCMP; the red dashed line indicates a p value of 0.05) (c), average low-q intensity (d), integrated intensity (calculated as described by Hopkins & Thorne, 2016) (e), I(0) (obtained from DATGNOM) (f), Porod volume (obtained from DATPOROD) (g), molecular weight (calculated as described by Fischer et al., 2010) (h), radius of gyration [from linear regression of Guinier plots in SigmaPlot 13 (shown in Supplementary Fig. S3); the solid grey line indicates our observed Rg for undamaged RNase A of 16.2 ± 0.2 Å] (i), maximum particle size (Dmax, from DATGNOM; the solid grey line indicates the undamaged RNase A Dmax of 42.8 ± 0.5 Å) (j), indicate large differences between conventional (blue circles) and coflow (red squares) in the response of RNase A to increasing flux. The solid black lines indicate linear regression of the increases in the various parameters; the dashed grey lines indicate 95% confidence intervals of the linear fit. |