A fluid transfer system has a holder that is made of a cylindrical member having a closed end and an open end. The closed end has fitted thereto a luer and a cannula that extends into the interior of the holder. The holder has a distal portion that has a first cross section and a proximal portion that has a second cross section. The cross section of the distal portion is smaller than the cross section of the proximal portion. The distal and proximal portions are joined by a shoulder. The fluid transfer system also includes an adapter that is inserted, to the holder from the open end of the holder. The adapter has a base having a central opening and a cylindrical tube that extends from the central opening. The diameter of the cylindrical tube is slightly smaller than the diameter of the distal portion and is configured to accept a first type of fluid collection store such as a vacuum tube. A non-continuous wall extends from the base of the adapter to surround the cylindrical tube. The cross section of the wall is slightly smaller than the diameter of the proximal portion. At each section of the non-continuous wall there is formed a protuberance. A groove is formed about the inner surface of the proximal portion. When the adapter is fully inserted to the holder, the protuberances would snap fit to the groove so that the adapter is prevented from being inadvertently removed from the holder. With the adapter removed, the holder can accept a differently dimensioned fluid collection store such as for example a blood culture collection bottle.Linvention concerne un système de transfert de liquides qui comprend un support composé dun élément cylindrique muni dune extrémité fermée et dune extrémité ouverte. Un Luer et une canule sadaptent dans lextrémité fermée et sétendent à lintérieur du support. Le support possède une partie distale qui présente une première coupe transversale et une partie proximale qui présente une seconde coupe transversale. La coupe transversale de la
