Sticky and blunt ends#Overhangs and sticky ends

Sticky end (English for " sticky end " ) or adhesive end means the end of a DNA segment, if one of the two single strands protrudes a few bases beyond the end. If that is the case, another DNA strand can attach end it with complementary thereto matching sticky - hence the name. The opposite - that is, the end of a DNA double strand without overhang - called blunt end (English for " blunt end ").

Sticky ends arise especially when restriction cleavage with certain restriction enzymes.

Example: restriction cleavage with the enzyme EcoRI

5'- GAATTC -3 ' 3'- CTTAAG -5 ' 5' -G AATTC -3 ' 3'- CTTAA G -5 ' As the recognition sequences of the restriction enzymes are palindromic, the two resulting sticky ends are identical.

Most of the sticky ends are desirable because they targeted linking of DNA strands allows (see ligation ). To this end, the two desired DNA fragments are cut with the same enzyme and consequently exhibit matching sticky ends.