Abstract: The present invention relates to a container for storing a reagent, the container comprising: a storage space for reagent (R) comprising a flexible pouch; a passage having a first end (4) that opens onto the outside of the container and a second end that opens into the storage space, the passage being designed to allow a sampling device (20) to access the storage space; a deformable partition (7) that closes off the passage when said partition is not mechanically loaded and which can be loaded by the sampling device to a position in which the passage is open; a seal (6) that is positioned in the passage and comprises an elastically deformable rim (64) defining an orifice (61) that is designed to receive part of the sampling device (20), said rim (64) being designed to establish a seal together with the outer walls of the sampling device when said device is introduced into the passage.