A medical device for separating a fluid, in particular for separating platelet-rich plasma from whole blood, includes three containers and at least one corresponding connection line having an intermediate bifurcation. Provided on the connection line are valve means for enabling or preventing a flow of fluid. At least one container includes a hollow container body and a plunger associated in a movable way to the container body. A modular structure has modules connected to enable separation thereof A first module includes at least the first container and a corresponding portion of the first connection line, and a second module, which has at least one between the second and third containers with a corresponding portion of the first connection line. Provided at least at the interface between two modules of the modular structure are releasable connectors, in particular hydraulic connectors having at least two parts that can be coupled together, each of which belongs to a corresponding module.
