FIG. 3.

The G-strand overhang is elongated in Ku86-heterozygous cells. (A) Genomic DNA was purified from the indicated cell lines and either left untreated (−) or digested overnight (+) with ExoI. The DNA was subsequently purified, digested to completion with MboI and AluI, and then subjected to terminal restriction fragment Southern blot analysis under nondenaturing (Native) conditions with a (C₃TA₂)₃ 5′-end-radiolabeled oligonucleotide probe. (B) The gels shown in panel A were denatured and rehybridized with the identical probe (Denatured). Exp., experiment.