Mapping Dnase-I-hypersensitive Sites Protocol Protocol describes how isolated nuclei are incubated with varying amounts of Dnase I. Genomic DNA is then isolated from the nuclei and digested with a restriction enzyme, analyzed by gel electrophoresis, and probed by Southern hybridization.
Mapping Protein-binding Sites on DNA by 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.
