Sticky ends

Sticky ends are fragments of DNA where one strand, after being cleaved by restriction enzymes, is left over hanging another strand. These overhangs are termed 'sticky' because they can easily bind to free nucleotides . Restriction enzymes can also symmetrically cleave DNA strands to form blunt ends.

Some examples of Restriction endonucleases that cut to create 'sticky ends' are:

BamHI, BaI228I and EcoRI