The invention relates to a device for producing a fluid containing a radioactive constituent, the device comprising: a shielded chamber (5) within which is located an isotope container (6) housing a radioactive isotope (7), the shielded chamber including first and second fluid connections (12,13) to opposing ends of the isotope container and a fluid conduit (14,15) extending from each of the first and second fluid connections to a fluid inlet (16) and a fluid outlet (17) respectively characterised in that the fluid inlet comprises a single spike (22) having a substantially circular cross-section, the spike being adapted to penetrate the rubber seal of a vial and the spike having two bores, the first bore extending from a first aperture adjacent the tip of the spike to a fluid connection with the fluid conduit and the second bore extending from a second, separate aperture in the spike to a filtering air inlet.