Comparison of clonogenic assay with premature chromosome condensation assay in prediction of human cell radiosensitivity

Table 1 Parameters of cell survival and non-rejoining G2-chromatid breaks of the three cell lines after exposure to γ-rays irradiation

Cell line	α(Gy -1)1	β(Gy -2)1	SF22(mean ± SE)	Slope3(mean ± SE)
HepG2	0.2	0.075	0.455 ± 0.06	2.17 ± 0.225 (r = 0.974)
HO8910	0.08	0.065	0.652 ± 0.07	1.83 ± 0.013 (r = 0.987)
L02	0.04	0.05	0.863 ± 0.09	1.134 ± 0.06 (r = 0.992)

¹α and β values were determined from the linear quadratic equation.

²Survival fraction at 2 Gy was measured from the raw data.

³Slope from the fitted linear regression represents non-rejoining G2-chromatid breaks per cell per unit dose.

Table 2 Correlation between non-rejoining G2 chromatid breaks and cell survival

	Dose (Gy)	r	P
Multiple	2+4	0.874	0.023
	2+4+6	0.886	＜ 0.01
	0.5+1+2+4+6+8	0.923	＜ 0.001