Stereotaxically placed guide cannulas allow for insertion of biosensors post-surgery. For single or dual biosensor implantations in mice the BASi mouse guide cannula (7032) is recommended for use. The guide cannula is also recommended for dual implantations in rats. The 7032 guide cannula shaft is 5 mm in length and approximately 600 μm in diameter. The smaller size of the cannula allows for contra-lateral implantation of biosensors at a minimum distance of approximately 3.2 mm.