Table 1

Table 1. Incidence of bends that are large (1.1 rad) or medium-large (0.8 rad), at contour separations L = 5 nm and 10 nm. The first three rows restate points made in the figures. Each of the columns labelled 'fraction' show that our data disagree significantly with the predictions of the WLC model (Fig. 2c), but agree with our model (Fig. 3a). The angles quoted refer to the angle between the vectors t and t' in Fig. 1c. Row 1: experimental results from our main data. The large absolute numbers emphasize that our conclusions are not merely based on a handful of images. Row 2: expected results from a Monte Carlo evaluation of the WLC model with persistence length  = 54 nm. Row 3: expected results from Monte Carlo evaluation of our model with the same long-scale behaviour. The remaining rows show results of control experiments and a more detailed calculation (see Supplementary Information). Row 4: experimental data obtained using DNA incubated with ligase. Row 5: experimental data obtained when DNA was adsorbed to V1-grade mica. Row 6: numerical results when the WLC configurations generated by the Monte Carlo code (row 2) were converted to simulated AFM traces and then sent through our image analysis (solid curve in Fig. 2c and Supplementary Information, Fig. S8).

	Points separated by L = 5 nm					Points separated by L = 10 nm
	No. of pairs	No. of large bends	Fraction  104	No. of medium bends	Fraction  104	No. of pairs	No. of large bends	Fraction  104
Experimental data	93,895	82	8.7	746	79	92,725	969	100
WLC	3,122,109	91	0.29	6,848	22	3,105,187	17,678	57
LSEC equation (1)	2,922,111	2,756	9.4	21,809	75	2,906,273	28,773	99
Experimental with ligase	51,303	42	8.2	469	91	50,699	467	92
Experimental with V1-grade mica	30,597	18	5.9	263	86	30,263	326	110
WLC simulated	200,152	11	0.55	568	28	185,164	1,089	59