Figure 2. Controls for invading strand experiments with surface-bound 427/352 nt hybrid DNA.

(a). Bead-labeled, homologous ssDNA substrates with ADP did not form stable tethers. (b). Bead-labeled, heterologous ssDNA. (c). Bead-labeled, homologous ssDNA substrates but without RecA and ATP. The upward arrow indicates the disappearance of the tethered bead, suggesting that the reaction did not proceed.