Transgenic embryo yield is increased by a simple, inexpensive micropipet treatment.

A method for the treatment of micropipet tips for injection of DNA into pronuclei of mouse embryos is described. The method requires only standard laboratory equipment, a magnetic stirrer and an inexpensive commercially available grinding powder. The method involves little extra time and no special skills. After introduction of the method, the time required for injections was reduced by about 30%, and the yield of surviving embryos was increased by 28%.