A dosing method using a device for transferring and dosing biomedical fluids between hospital containers includes a syringe body containing a biomedical fluid and a piston sealed fitted therein, the syringe body including a first extremity having joining elements to a first container and to a second container, and a second extremity opposite the first extremity, the method including gripping a handle having a coupling seat for fastening to the second extremity placing first temporary fastening elements between the coupling seat and second extremity placing second temporary fastening elements between the piston and thrust rod operating a thrust rod of a motorized element mounted in the handle for pushing the piston and dosing using control elements mounted on the handle, associated with the motorized element to dose volumetric quantities of biomedical fluid from the first container and dispensing to the second container.