It has happened to us all; you run a gel expecting one or two bands, but end up with additional, unexpected bands of varying size and intensity. Typically, these off-target bands are caused by either star activity or partial digestion. Yvette explains both of these phenomena, and gives tips for avoiding them in the future, including optimizing incubation time and using NEB’s High-Fidelity (HF®) Restriction Enzymes.