Practice question

When digestion is partial, the DNA population becomes heterogeneous with molecules cleaved at different combinations of sites, generating many overlapping fragment lengths. Instead of crisp discrete bands, closely spaced intermediates may appear blurred, especially if site spacing is small or agarose resolution is limited, producing smear-like zones. Gel drying, overloading, or absence of buffer cause general distortion, not site-specific heterogeneity. The fundamental cause of variable digestion states is inconsistent cleavage efficiency across molecules, creating multiple subpopulations migrating at different positions.