Figure 3.

The strand displaced during the DNA strand exchange in trans is intact. The ³²P-labeled DNA strand (#1) that was displaced from dsDNA (#1 and #2) during DNA strand exchange in trans was isolated (see Materials and Methods) and analyzed by electrophoresis on a 10% polyacrylamide gel containing 50% urea (displaced ssDNA), along with the original ³²P-labeled oligonucleotide (#1; substrate ssDNA). ³²P-labeled DNA migration markers (marker) were obtained by cleavage of the oligonucleotide #2 at adenine and guanine residues according to Maxam and Gilbert (1980).