In radio astronomy, interstellar isotope ratios have been measured for more than two decades towards different parts of the Milky Way and central regions of some star-burst galaxies. While signals are often too weak to detect rare isotopic species in relatively distant extragalactic sources, our Galaxy only provides an environment with limited metallicity range. Obviously, this constraint can be removed by observing isotopic species in the Magellanic Clouds, located only 50–60 kpc away from us. We thus observed isotope ratios of hydrogen, carbon, nitrogen, oxygen, and sulfur and the results are given in Table 1.