互补的核苷酸的相互作用。由于DNA是一种通过互补作用形成的双链结构（C和G，A和T），当互补链被打断时就会发生重新相互连接或杂交。若有相配的碱基序列，这种情况会发生在DNA和RNA链之间。杂交可以发生在包括复制、转录在内的所有DNA反应中，是Southern和Northern,PCR以及测序的分子生物学基础。

The interaction of complementary nucleic acid strands. Since DNA is a double-stranded structure held together by complementary interactions (in which C always binds to G, and A to T), complementary strands favorably reanneal or “hybridize” to each other when separated. This can occur between two DNA strands and also between DNA and RNA strands provided there is sufficient complementarity in their base sequence. Hybridization occurs in all physiological DNA reactions including replication, and transcription, and forms the basis of many molecular biology techniques including Southern and Northern blotting, PCR and sequencing.