Analysis of DNA dimensions with SFMetrics. A) DNA contour-length of one DNA molecule (pUC19, center molecule in Figure 2 cropped area) has been traced by hand (red line) with the ‘Plot line’ tool. Orthogonal yellow lines to the freehand-traced line represent the cross-sections of the molecule used for extracting the height and for calculating the FWHM. B) DNA height along the freehand-traced. Maximum height from each cross-section (yellow lines in panel A) is plotted against length along the red line. C) Example analysis of one cross-section line from panel A. Height along the line (black crosses) is plotted against pixel position. Red line is the normal fitting to the data from where standard deviation is calculated and use for computing the FWHM. D) DNA width analysis along the freehand-traced. FWHM from each cross-section (yellow lines in panel A) is plotted against length along the red line.