If you cut and you open up a segment of DNA then you've left these sticky ends, for example and these sticky ends are capable of recognizing each other by the process of hybridization.

如果你进行切割打开一个DNA片段,就会留下,比如说,这些粘性末端,这些粘性末端能在杂交的过程中互相识别

耶鲁公开课 - 生物医学工程探索课程节选