A containment device for biological samples, which comprises:a first vessel for depositing a biological sample,a lid adapted to engage the first vessel,a hermetically-sealed chamber, adapted to contain a preservative, arranged between the lid and the first vessel,elements of generating a passage between the hermetically-sealed chamber and the first vessel for the descent of the preservative from the chamber to the first vessel；the hermetically-sealed chamber is defined by a second vessel, which is inserted into the first vessel with the filling opening directed toward the lid, and by the lid itself, closed onto the first vessel,the elements of generating a passage between the hermetically-sealed chamber and the first vessel comprise a region with a pre-fracture that is defined on the second vessel and a corresponding presser that extends from the lid and is in a position to encounter the region with a pre-fracture.
