An injection member penetrates an elastic septum of a device defining a sealed, empty, sterile chamber in fluid communication with the septum. During penetrating, an annular interface is formed between the septum and the injection member extending axially between a penetration point on an interior surface of the septum in fluid communication with the sterile chamber, and an exterior surface of the septum engaging the injection member. The injection member is de-contaminated by (i) friction between the septum and injection member at the annular interface, and (ii) elongation of the septum at the annular interface. A substance is introduced through the injection member and into the sterile chamber of the device, the injection member is then withdrawn from the septum, the septum reseals itself at the resulting penetration aperture, and the chamber is maintained sterile throughout the foregoing steps.