“But when it enters E. coli, the linear DNA gets converted to a circular molecule because the viral DNA has sticky—or cohesive—ends,” said Mertz. She hypothesized that this also happened with ...

When they act on a DNA molecule, restriction enzymes produce "blunt" ends when they cut in the middle of the recognition sequence, and they yield "sticky" ends when they cut at the recognition ...

After two fragments with complementary sticky ends are joined, the DNA backbone may be covalently sealed using another enzyme called DNA ligase.