(E) Left image shows an observed, EdU-labeled vDNA focus. Right: simulations of a single linear or circular 10 Kb long chromatinized DNA polymer chain and corresponding predicted images in diffraction-limited (~300 nm resolution) microscopy. (F) Boxplots show the distribution of sizes (FWHM, full width at half maximum) of n=40 measured vDNA foci (for MOI 100) compared to the sizes predicted for linear (left) and circular (right) chains based on n=100 simulated configurations each. Blue lines in boxes define medians, top and bottom limits define upper and lower quartiles, respectively. Whiskers show the full data range, except for outliers. Grey dots are individual data points. All differences are highly significant (Wilcoxon test data vs. model: ***p ≈ 3 ⋅ 10 − 20, circular vs. linear model: ***p ≈ 10 − 17). 