所谓黏性末端或黏状末端（'Sticky Ends'），指DNA重组技术中，DNA限制酶在切开DNA的双链结构时，形成的突出末端，与平末端（'Bluent Ends'）相对。平末端则是上述切割过程中不突出的末端，所以DNA重组时操作难度稍大于黏性末端。

DNA end or sticky end refers to the properties of the end of a molecule of DNA or a recombinant DNA molecule. The concept is important in molecular biology, especially in cloning or when subcloning inserts DNA into vector DNA. All the terms can also be used in reference to RNA. The sticky ends or cohesive ends form base pairs. Any two complementary cohesive ends can anneal, even those from two different organisms. This bondage is temporary, however, and DNA ligase will eventually form a covalent bond between the sugar-phosphate residue of adjacent nucleotides to join the two molecules together.