... R- loops were incubated with or without EcoRI or endoG. (A)Heavy strand. The cleavage sites were determined by primer extension using the primer FD7. Lanes T, G, C, and A indicate sequence ladders ... and 1.0% TritonX-100 were added, and the samples were centrifuged at100 000 g for 30 min and separated into pellets and supernatants. The pellets were suspended in the samevolume of buffer, ... polymerase (Takara, Seta, Japan). For sequenceladders, 25 cycles of primer extension reactions weresimilarly performed, but using a Thermo Sequence CoreSequencing kit (Amersham Pharmacia Biotech) and...