\b[It is the free labelled <DNA> probe], not bound in the slower-moving <protein>–<DNA> complexes. Its smaller effective hydrodynamic size allows faster migration. Excess unbound probe commonly gives a strong lower band; a probe-only lane would verify this assignment and distinguish it from a labelled degradation product.

Solution

Past exam of the biochemistry and Molecular Biology course of the University of Cambridge / 2025 / Paper 2 / Section C / 14 / k / Solution

 Solution (source code)