Hybridization is one way to determine the sequence of a DNA strand from detecting the changes in the length of a hairpin. When a probe hybridizes to an open hairpin, complete refolding of the hairpin is stalled, and the position of the hybridized probe can be inferred. Thus the sequence of a DNA fragment of interest can be inferred from overlapping the positions of probes sets, which are allowed to hybridize one by one.