Which technique separates DNA based on conformation and density?
CsCl density gradient centrifugation uniquely separates DNA species based on conformation and buoyant density in an isopycnic gradient. Supercoiled, nicked, and linear DNA differ in capacity to intercalate EtBr, resulting in distinct buoyant densities and band positions. Silica columns and magnetic beads purify by adsorption based on chemical interaction with matrix, not conformation. GITC lysis denatures proteins for extraction but does not resolve topology. Therefore only CsCl centrifugation discriminates DNA forms by supercoiling, linking conformational state to measurable density differenc
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.
