A liquid supply interface (62; 62'; 62"; 62"') for a cell culturing system for supplying cell cultures found in different cell culture containers (10; 10'; 10") with a nutrient medium, wherein the liquid supply interface (62; 62'; 62"; 62'") comprises: a housing defining a flow area, a first connection formation for the liquid-transferring connection of a first fluid line to the housing, a second connection formation formed separately from the first for the liquid-transferring connection of a second fluid line to the housing, a third connection formation formed separately from the first two for the liquid-transferring connection of the housing to a third fluid line, a coupling formation (64, 66) formed separately from the connection formations (76, 78, 80), which is formed for the producible and detachable liquid-transferring coupling contact according to the operation, with a corresponding counter-coupling formation (38, 40) of a cell culture container (10, 10', 10"), a first liquid flow path, which extends between the flow area and the first connection formation for introducing a first liquid from the outside into the flow area, a second liquid flow path, which extends between the flow area and the second connection formation for introducing a second liquid different from the first from the outside into the flow area, a third liquid flow path, which extends between the flow area and the third connection formation for removing a liquid from the flow area, and a coupling flow path (44a, 47a), which extends between the flow area and the coupling formation (64, 66) in order to remove a liquid from the flow area and/or to introduce it to said flow area via the coupling formation (64, 66), wherein the first, the second and the third liquid flow path each have a valve configuration, which is completely surrounded - with the exception of the respective liquid flow path - by the housing and incorporated in it, without a continuous signal and/or power-transferring physical connection from the valve configuration up to the outside of the housing, wherein a control configuration with a signaling means generating an electric and/or magnetic and/or electromagnetic field is assigned to each valve configuration, the field of which acts upon a correspondingly field sensitive counter-signaling means of the valve configuration without contact, wherein each valve configuration can be switched via the field, acting upon its counter-signaling means, between a blocked position, in which the valve configuration interrupts a liquid flow in the liquid flow path (82, 90, 92) in which it is arranged, and an outlet position in which the valve configuration enables a liquid flow. a housing defining a flow area, a first connection formation for the liquid-transferring connection of a first fluid line to the housing, a second connection formation formed separately from the first for the liquid-transferring connection of a second fluid line to the housing, a third connection formation formed separately from the first two for the liquid-transferring connection of the housing to a third fluid line, a coupling formation (64, 66) formed separately from the connection formations (76, 78, 80), which is formed for the producible and detachable liquid-transferring coupling contact according to the operation, with a corresponding counter-coupling formation (38, 40) of a cell culture container (10, 10', 10"), a first liquid flow path, which extends between the flow area and the first connection formation for introducing a first liquid from the outside into the flow area, a second liquid flow path, which extends between the flow area and the second connection formation for introducing a second liquid different from the first from the outside into the flow area, a third liquid flow path, which extends between the flow area and the third connection formation for removing a liquid from the flow area, and a coupling flow path (44a, 47a), which extends between the flow area and the coupling formation (64, 66) in order to remove a liquid from the flow area and/or to introduce it to said flow area via the coupling formation (64, 66), wherein the first, the second and the third liquid flow path each have a valve configuration, which is completely surrounded - with the exception of the respective liquid flow path - by the housing and incorporated in it, without a continuous signal and/or power-transferring physical connection from the valve configuration up to the outside of the housing, wherein a control configuration with a signaling means generating an electric and/or magnetic and/or electromagnetic field is assigned to each valve configuration, the field of which acts upon a correspondingly field sensitive counter-signaling means of the valve configuration without contact, wherein each valve configuration can be switched via the field, acting upon its counter-signaling means, between a blocked position, in which the valve configuration interrupts a liquid flow in the liquid flow path (82, 90, 92) in which it is arranged, and an outlet position in which the valve configuration enables a liquid flow.