Lambda Digest DNA
Force measurement of a single tethered Lambda-digest DNA molecule. During the extension of the molecule (red trace), the DNA first goes through the B-S transition (the plateau), and then melts to single-stranded DNA (ssDNA) at a higher force. During relaxation (purple trace), the DNA doesn't always re-anneal so the B-S transition isn't always present.
Sample courtesy of H. Claussen-Schaumann and R. Krautbauer, Gaub Lab, Ludwig Maximilians University.