Practice question

During CTAB extraction, high salt concentration is maintained to keep DNA soluble while acidic polysaccharides are precipitated by CTAB. Upon lowering salt concentration below 0.5 M NaCl, DNA forms insoluble CTAB-DNA complex and precipitates. Neutral polysaccharides, which lack acidic groups, do not interact strongly with cationic CTAB and remain soluble in the supernatant even at low salt, thus they are effectively separated from DNA. Acidic polysaccharides, nucleic acids, and DNA-CTAB complex are removed or precipitated during steps, while neutral polysaccharides remain in solution.