A virus inactivation device for a liquid chromatography system, comprising: an inlet port; an outlet port; a virus inactivation means configured to inactivate viruses during a predetermined virus inactivation time; a group of containers (104,105,106), wherein each container in the group has a volume and a moveable sidewall arranged to divide the volume into an opposed first sub-volume and a second sub-volume, wherein each container comprises a first port connected to the first sub-volume and a second port connected to the second sub-volume; a fluid controller connected to the inlet port, to the outlet port and to the first port and to the second port of each container in the group, respectively; wherein the fluid controller is configured to: select a container that is empty or has been in a filled state during a time equal to or longer than the virus inactivation time; direct the fluid flow from the inlet port to a first or second port of an empty sub-volume of the selected container in the group; when the sub-volume of the selected container is filled, direct the flow to another empty sub-volume of another container in the group, which container is empty or has been in a filled state during a time equal to or longer than the virus inactivation time, whereby fluid pressure resulting from the filling of the empty sub-volume acts on the moveable side wall to cause the opposing filled sub-volume to flow its content to the outlet port. an inlet port; an outlet port; a virus inactivation means configured to inactivate viruses during a predetermined virus inactivation time; a group of containers (104,105,106), wherein each container in the group has a volume and a moveable sidewall arranged to divide the volume into an opposed first sub-volume and a second sub-volume, wherein each container comprises a first port connected to the first sub-volume and a second port connected to the second sub-volume; a fluid controller connected to the inlet port, to the outlet port and to the first port and to the second port of each container in the group, respectively; wherein the fluid controller is configured to: select a container that is empty or has been in a filled state during a time equal to or longer than the virus inactivation time; direct the fluid flow from the inlet port to a first or second port of an empty sub-volume of the selected container in the group; when the sub-volume of the selected container is filled, direct the flow to another empty sub-volume of another container in the group, which container is empty or has been in a filled state during a time equal to or longer than the virus inactivation time, whereby fluid pressure resulting from the filling of the empty sub-volume acts on the moveable side wall to cause the opposing filled sub-volume to flow its content to the outlet port. select a container that is empty or has been in a filled state during a time equal to or longer than the virus inactivation time; direct the fluid flow from the inlet port to a first or second port of an empty sub-volume of the selected container in the group; when the sub-volume of the selected container is filled, direct the flow to another empty sub-volume of another container in the group, which container is empty or has been in a filled state during a time equal to or longer than the virus inactivation time, whereby fluid pressure resulting from the filling of the empty sub-volume acts on the moveable side wall to cause the opposing filled sub-volume to flow its content to the outlet port.