Container assembly (300), comprising - a container (1) configured to store a sample (45) of tissue； said container (1) comprising a bottom (13)； - a cover (2) adapted to engage with said container (1), said cover (2) comprising: - an upper member (21) comprising a receptacle (211), said receptacle (211) being adapted to contain a preservative agent , - a seal (22), to seal said receptacle (211)； characterized in that said cover (2) additionally comprises: - a drilling member (323), configured to break said seal (22) by displacing said drilling member (323)； wherein the container assembly (300) has a first and a second position, in which in the first position the container (1) is isolated from the receptacle (211), and in the second position fluid communication is provided between the receptacle (211) and the container (1) and in which the container assembly (300) comprises a separator (31) positioned between the seal and the bottom (13) of the container (1) and, the separator (31) is provided of at least one opening (291) adapted to provide a fluid passage between the receptacle (211) and the container (1).Conjunto (300) de recipiente, que comprende - un recipiente (1) configurado para almacenar una muestra (45) de tejido； comprendiendo dicho recipiente (1) un fondo (13)； - una cubierta (2) adaptada para acoplarse con dicho recipiente (1), comprendiendo dicha cubierta (2): - un miembro superior (21) que comprende un receptáculo (211), estando dicho receptáculo (211) adaptado para contener un agente conservante, - un sello (22), para sellar dicho receptáculo (211)； caracterizado por que dicha cubierta (2) comprende adicionalmente: - un miembro de perforación (323), configurado para romper dicho sello (22) mediante el desplazamiento de dicho miembro de perforación (323)； en el que el conjunto (300) de recipiente tiene una primera y una segunda posición, en el que en la primera posición el recipiente (1) está aislado del receptáculo (211), y en la segunda posición se p
