¹³⁷Cs gamma-ray irradiation inhibits the viability of tumor cell lines <i>in vitro</i>.

<p>After ^<b>137</b>Cs gamma-ray irradiation (0, 30, 50 and 100 Gy), HepG2 (A), SW620 (B), and SGC7901 (C) cells separated from human erythrocytes were cultured for 24 h, (D) 48 h and 72 h, and then the viability was detected by MTT assay. The cell viability was indicated by the percentage of viable cells. Date are means ± SEM; <i>n</i> = 6 erythrocyte samples from 6 volunteers in each group. Con: the dose of irradiation was 0. *<i>P</i><0.05 vs. the same treated group cultured for 24 h; ^<b>#</b><i>P</i><0.05, ^<b>##</b><i>P</i><0.01 vs. 30 Gy irradiation group at the same culture time; ^<b>+</b><i>P</i><0.05 vs. 50 Gy irradiation group at the same culture time.