The device has a tube (2), which is closed at its upper open end in a vacuum-sealed manner and is provided with a cap (5). The cap has a dome-like projection (6) for holding a cannula or double cannula supported by a needle holder. The cap accommodates a membrane (7) at its front end, where the membrane is penetrated by the cannula. The cap and the tube are made of gas-impermeable material, particularly polyethylene terephthalate. A plug-free sealing element (4) is formed between the cap and the tube.