Petitioner seeks certiorari review of an order requiring scientific testing as to the paternity of a child. Here the paternity of the child had been conclusively established by previous rulings and was thus protected by the doctrine of res judicata. We grant the writ on the authority of Department of Revenue v. Goulbourne, 648 So.2d 856 (Fla. 4th DCA 1995), and quash the order under review.