- Both create a banding pattern
- unique for each individual.
1. DNA containing the gene of interest is extrcted from human cells and cut into fragments by restriction enzymes.
2. The fragments are separated according to size by gel electrophoresis. Each bands consists of many copies of a particular DNA fragment. The bands are invisible but can be made visible by staining.
3. The DNA bands are transferred to a nitrocellulose filter by blotting. The solution passed through the gel and filtered to the paper towels.
4. This produces a nitrocellulose filter with DNA fragments positioned exactly as on the gel.
5. The filter is exposed to a radioactively labeled probe for a specific gene. The prode will base-pair (hybridize) with a short sequence present on the gene.
6. Th filter is then exposed to x-ray film. The fragment containing the gene of interest is identified by a band on the developed film.