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. With the adapter removed, the holder can accept a differently dimensioned fluid collection store such as for example a blood culture collection bottle.