Protocol for Dnase I footprinting. Includes: Labeling of probe; Synthesis of probe by PCR; Dnase I foot printing. - [Read Dnase I Footprinting Protocol]
Dnase I is used to fragment a radiolabeled target DNA in the presence and absence of a nuclear extract. A "footprint" is generated when a protein binds to the target and protects a specific segment of DNA from the nucleolytic activity of Dnase I. By comparing the electrophoretic mobility of the Dnase I cleavage products to those of a sequence ladder derived from the same DNA fragment, the position(s) of the DNA sequences recognized by DNA-binding proteins can be determined. - [Read Mapping Protein-binding Sites on DNA by Dnase I Footprinting Protocol]