Practice question

EDTA (ethylenediaminetetraacetic acid) is a chelating agent essential in DNA isolation buffers. It binds divalent cations like Mg2+ and Ca2+ with high affinity, forming stable coordination complexes. Mg2+ is a crucial cofactor for DNases that degrade DNA and for nucleases that destabilize membranes. By sequestering Mg2+, EDTA irreversibly inhibits endogenous nuclease activity, protects genomic DNA from enzymatic degradation, and helps destabilize cell walls by removing membrane-stabilizing cations. It does not denature proteins directly, bind nucleic acids specifically, or degrade RNA; its function is strictly chelation-mediated protection and enzymatic inhibition.