Which method allows immunoprecipitation of protein-DNA complexes?
Chromatin Immunoprecipitation is definitive technique for immunoprecipitating protein-DNA complexes from living cells. Cells are crosslinked with formaldehyde to covalently stabilize transient protein-DNA contacts. Chromatin is sheared by sonication or micrococcal nuclease to fragments of 200-500 base pairs, incubated with antibody specific to transcription factor or histone modification, captured on protein A or G beads. After extensive washing, crosslinks are reversed, proteins digested, DNA purified for PCR or sequencing. This in vivo approach directly identifies genomic loci occupied, unli
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
