Practice question

Asymmetric restriction site placement on linear DNA creates fragments of three distinct lengths upon complete digestion. With two sites, cuts produce left terminal segment, central inter-site segment, and right terminal segment. If distances from ends and inter-site distance differ, all three fragments differ in molecular weight and resolve as three separate bands on agarose gel. Symmetric placement would cause two bands to co-migrate. Therefore asymmetric distribution guarantees maximum band separation, aiding accurate measurement of each inter-site distance during physical mapping.