A valve (2), crossed by at least one channel (3), allowing to direct at least one fluid (F5) displaced by a transfer device within a test sample card (1), the card (1) featuring two faces (4 and 5) connected to one another (4) (5) by an edge (6). A card equipped with a device allowing several cards equipped with such valves to be implemented is made up of a flexible film (7), and/or which can be distorted, part of which is fixed to at least one of the faces (4 and/or 5) of said card (1) on the one hand, and a film compression device (7), which can be deactivated on the other hand. In addition, securing is carried out on at least one of the plane faces (4 and/or 5), for example, by a securing device located at the level of a recession (9) peripheral to the valve (2), such as a groove (9). The valve is particularly applicable in the field of diagnosis.