ABSTRACT
Ear notching or punching is a long-term identification method that can be performed quickly with little pain or distress. Mice are restrained by the scruff, and using an ear punch, holes or notches are placed in the ears following a simple identification chart. Removed tissue can be used for genotyping, possibly replacing the need for a tail biopsy. Care must be taken when placing the punches. Punches too close to the edge of the ear may be ripped or torn open by the mouse, leaving patterns hard to identify.
