What characterizes a sticky end after a restriction digest?

A sticky end, resulting from a restriction digest, is characterized by DNA ends that can easily bind with complementary sequences. This occurs because the enzymes used in the restriction digest cut the DNA in a staggered manner, leaving single-stranded overhangs at the ends of the DNA fragments. These overhangs are capable of forming hydrogen bonds with complementary overhangs from other DNA fragments, which is essential for processes such as cloning or DNA assembly.

In contrast, blunt ends, which do not have overhangs, result in fragments that have been cut evenly with no single-stranded regions available for hybridization. This makes them less effective for certain applications where ligation is desired. Fragments that cannot hybridize would not be compatible for techniques relying on base pairing, limiting their usability. Additionally, DNA segments with no specific sequences do not provide complementary bases for binding, further distinguishing the unique feature that sticky ends bring to molecular biology practices.