Table 1.

Persistence length calculated using different statistical descriptors of the WLC model for various mounting and imaging conditions

Mounting conditions	Scored length (nm) (No. molecules)	P〈R2〉 (nm)	P〈cos〉 (nm)	P〈θ2〉 (nm)	P〈D4〉 (nm)	Avg. (nm)
2.5 mM NaCl∗	∼33,000 (210)	30	29	29	29	29
10 mM NaCl∗	∼70,000 (451)	31	31	33	34	32
50 mM NaCl∗	∼37,000 (235)	35	31	32	30	32
100 mM NaCl∗	∼76,000 (490)	25	25	26	25	25
1 mM NaCl, polylysine†	∼107,000 (685)	26	23	25	23	24
2.5 mM NaCl, polylysine†	∼52,000 (332)	28	26	27	23	26
10 mM KCl, 5 mM MgAc2†,‡	∼134,000	23	20	22	23	22
10 mM KCl, 5 mM MgAc2†,§	∼151,000	23	21	24	27	24
10 mM KCl, 5 mM MgAc2†,¶	∼112,000	21	19	22	26	22
10 mM KCl, 5 mM MgAc2†,‖	∼1,000,000	89	80	81	66	79
10 mM KCl, 5 mM MgAc2†,∗∗	∼563,000	101	91	91	76	90

^∗474-bp DNA fragment, deposition onto glow-discharged carbon film, EM data.

^†474-bp fragment, deposition onto polylysine film, EM data.

^‡Mixture of 1144-bp and 1837-bp fragments, deposition onto glow-discharged carbon film, EM data.

^§2981-bp fragment, deposition onto glow discharged carbon film, EM data.

^¶Mixture of 474-bp and 2507-bp fragments, deposition onto glow-discharged carbon film, EM data.

^‖2981-bp fragment, deposition onto mica, AFM data.

^∗∗Mixture of 474-bp and 2507-bp fragments, deposition onto mica, AFM data.