Figure 3.

Fragmentation DNA induced by heat shock in TBY-2 cells. Cell cultures were treated at 55°C and returned to 27°C for a 72-h period. At the indicated time intervals after heat shock, cells were collected, frozen in liquid nitrogen, and genomic DNA was extracted as described in “Materials and Methods.” Five hundred nanograms of genomic DNA was separated on a 1.8% (w/v) agarose gel and detected by staining the gel with ethidium bromide.