FIG. 2.

Induction of chromosome breaks and micronucleus formation after cisplatin treatment. NIH 3T3 cells expressing JCV agnoprotein and control agnonegative NIH 3T3 cells were treated with cisplatin, and metaphase spreads were prepared as described in Materials and Methods. All photographs were taken at a magnification of ×700. (A) Agnonegative, untreated cells; (B) agnopositive, untreated cells; (C) agnonegative, cisplatin-treated cells; (D) agnopositive, cisplatin-treated cells. (E) Agnopositive and agnonegative cells were treated with 0, 0.125, or 0.25 μg of cisplatin/ml, and micronucleus (MIN) formation was measured as described in Materials and Methods.