Bag containing a biopharmaceutical product and probe holder port for such a product

A bag adapted to contain a biopharmaceutical product, said bag comprising:

• a flexible plastic sheath provided with at least one biopharmaceutical fluid input/output port and a measurement opening remote from the biopharmaceutical fluid input/output port, a first fastening zone surrounding said at least one measurement opening;
• a probe holder port produced in the form of a thin part, the probe holder port comprising a body provided with an axial through-bore and a peripheral flange comprising a second fastening zone and defining a fastening plane, the body extending from a side outside the flexible plastic sheath relative to the fastening plane, the first and second fastening zones being sealably assembled together by bonding or welding;
• a contact probe extending in the axial through-bore, being sealably assembled on the probe holder port, the contact probe comprising an active measurement end portion disposed in contact with the biopharmaceutical product when the bag is filled therewith, and an end portion opposite the active measurement end portion, the probe holder port comprising a transition portion between the body and the peripheral flange, the transition portion extending between a radially central end portion of the peripheral flange and a first axial end portion of the body said transition portion having a circumferentially continuous conical inner surface defining a cavity facing the at least one measurement opening and being axially disposed on an outer side relative to the fastening plane, the first axial end portion of the body being the axial end portion of the body that is closest to the radially central end portion of the peripheral flange, the first axial end portion of the body being disposed on the outer side relative to the fastening plane, the active measurement end portion being axially disposed on the outer side relative to the fastening plane.