Final answer:
The method used to introduce DNA into a single mouse cell is microinjection, which involves the precise injection of DNA directly into the cell's nucleus using a fine glass micropipette.
Step-by-step explanation:
Among the procedures listed, the method that would be used to introduce DNA into a single mouse cell is microinjection. This technique involves using a fine glass micropipette to directly inject DNA into the nucleus of a eukaryotic cell. The success of this method is due to its precision, as it allows the needle to penetrate both the cell membrane and nuclear envelope, enabling direct delivery of recombinant DNA to the cell's nucleus.