TABLE 2.

Pearson’s χ² Tests on Results of Micronucleus Experiments with Bystander Cells (BrdU⁻)

Experiment ID	Bystanders		Sham bystanders		P value
	Binucleates scored	MN frequency	Binucleates scored	MN frequency
3HdC21*	2012	0.028 ± 0.004	2035	0.028 ± 0.004	0.89
3HdC24	993	0.056 ± 0.007	990	0.038 ± 0.006	0.06
3HdC25	1990	0.036 ± 0.004	1997	0.031 ± 0.004	0.37
3HdC27	1468	0.044 ± 0.005	1998	0.028 ± 0.004	0.01
3HdC31	1842	0.029 ± 0.004	1955	0.024 ± 0.003	0.31
3HdC32	1988	0.023 ± 0.003	2008	0.022 ± 0.003	0.88
	Bystanders, 4 Gy γ rays		Sham bystanders, 4 Gy γ rays		P value
3HdC24	623	0.43 ± 0.03	656	0.52 ± 0.03	0.0007
3HdC25	994	0.50 ± 0.02	1266	0.46 ± 0.02	0.052
3HdC27	174	0.54 ± 0.05	684	0.45 ± 0.03	0.03

Notes. Micronucleus frequencies were compared in bystander and sham bystander cultures, as well as in bystanders and sham bystanders that were challenged with 4 Gy γ radiation to test for adaptive bystander effects. Statistical significance is α = 0.05. Data sets marked with * are plotted in Fig. 3B.