DNA footprinting to check binding regions in DNA

It's important to know in what regions of DNA proteins attach. DNA footprinting can show where binding regions are located. In the experiment, DNAse is used. DNAse cuts DNA in arbitrary positions. A sequence that has no proteins binding to it will have random cuts (all different sizes in equal amounts. However, if a protein is bind to it, the protein will protect close sequences from being cut. The DNAse will only cut parts far away from the binding site. Thus, a "gap" is produced. The samples are run in gel electrophoresis.

Proteins bind to DNA, and using DNA footprinting, it can be seen where. This is possible because the protein shields the sequences near it from the DNAse.