. 2002 Jul 1;30(13):2800–2808. doi: 10.1093/nar/gkf393

Table 2. Yields (F) for cluster induction derived from linear fitting of the data in Figures 5 and 6.

Cleavage agent	F (clusters/Mb/Gy) phosphate (P)	F (clusters/Mb/Gy) Tris–HCl (T)
Nfo protein	4.27 ± 0.12 (F_{P, Nfo})	0.032 ± 0.003 (F_{T, Nfo})
PUTR	8.85 ± 0.72 (F_{P, PUTR})	0.056 ± 0.002 (F_{T, PUTR})
Ratios R_i = F_{i, putr}/F_{i, endo} i = P or T	2.07 ± 0.06 (R_P = F_{P, PUTR}/F_{P, Nfo})	1.65 ± 0.17 (R_T = F_{T, PUTR}/F_{T, Nfo})

The number of clusters/Mb (y) were fitted to dose (x) according to the equation y = a + F·x (least mean squares fit). The ratios (R_i) of the frequencies for cluster induction by γ-rays in T7 DNA, detected by Nfo protein or PUTR, irradiated in phosphate (R_P) or 10 mM Tris–HCl (R_T), respectively, are also shown. The ratios were found to be statistically different at the 10% level (Fisher’s z-test).