Motivation

Many biological techniques are based on hybridization. For instance, consider the following situation: Let us take human DNA and oligos obtained from coding regions of mouse DNA (each one several hundred bases long). Let us now create a hybrid of the two. Since homology between these DNAs exists mostly in the coding regions, we can use the hybridization to infer where human coding regions are. If the oligos are tagged, either with fluorescent dye or radioactive label, one can detect where the oligos hybridized with the DNA, and thus infer what the coding regions are (or at least, which regions deserve further study).