Final answer:
To identify a specific DNA sequence in a genomic library, a labeled probe hybridizes with complementary DNA sequences on a nitrocellulose membrane, allowing for visualization of bound fragments.
Step-by-step explanation:
In the process of identifying a specific DNA sequence in a genomic library, a labeled probe is used. In the presence of a nitrocellulose membrane, this probe hybridizes with any DNA that has complementary nucleotide sequences. This hybridization is facilitated by the probe being labeled or tagged, often with a fluorescent dye, to visualize where the probe binds to the complementary DNA fragments. The process involves denaturation of the DNA, application of the probe to the nitrocellulose membrane, and detection through methods such as autoradiography or fluorescence scanning.