A simple and inexpensive particle-bombardment device, the OPgun™, was constructed for the
delivery of DNA into animal tissues. This device is based on the particle-inflow gun first described
for plant-cell transfection. The delivery of tungsten particles into the epidermis of the mouse ear,
without the use of vacuum and without causing damage to the tissue, was demonstrated. The system
was also shown to be capable of inducing antibodies to a foreign gene in mice.