A container (1) for in vitro diagnostic has a lower receptacle (2) designed to contain a non-toxic liquid (LS), an upper receptacle (3) designed to contain a toxic liquid (LF), and a connecting sleeve (4), in a threaded coupling with the lower receptacle (2) and the upper receptacle (3) for butt joining them. The connecting sleeve (4) has a transversal septum (40) being provided with a plurality of passage openings (48) and vent openings (49). When the container(1) is completely closed, both the lower receptacle (2) and the upper receptacle (3) abut the transversal septum (40). If the upper receptacle (3) is partially unscrewed with respect to the transversal septum (40), the toxic liquid (LF) flows by gravity into the lower receptacle (2). A method for storing a sample of human or animal tissue by using the container (1) is also provided.
