In a recent paper by Nevaldine et al. (1), DNA double-strand break (DSB) misrejoining after exposure to ionizing radiation was analyzed in double-minute chromosomes. The authors reported that elimination of broken DNA fragments by a pre-electrophoresis approach also eliminates misrejoined DNA. Based on their experimental results, Nevaldine et al. concluded that measurements of misrejoining using pulsed-field gel electrophoresis, rare-cutting restriction endonucleases, and Southern hybridization are likely to be compromised by artifacts such as apoptosis or necrosis since these processes generate broken DNA which might be more resistant to cleavage by rare-cutting restriction endonucleases sensitive to methylation. The authors further concluded that the key assumptions and consequently the conclusions of our DSB misrejoining measurements first published in ref. (2) are questionable.

A DSB rejoining study involving hybridization detection of large restriction fragments measures reconstitution of the intact fragment and hence...

You do not currently have access to this content.