Figure 3.

DEER results for GB1 T11C/V21C-CT02MA. (a) W-band ED-EPR spectra of HeLa cells frozen after incubation for 4 h (red) and 12 h (blue) postdelivery. The ED-EPR traces were normalized to the intensity of endogenous Mn(II). (b) Primary DEER traces and background function (gray) of the 4 h (red) and 12 h (blue) in-cell samples compared with the solution sample (50 μM in D₂O/glycerol-d₈, black). (c) DEER traces shown in panel b after background removal and the fitting traces obtained with Tikhonov regularization using DeerAnalysis (gray). (d) Distance distributions. The uncertainty range obtained using background decay validation for the in-cell sample is shown in light red.