Abstract: An improved pre-evacuated blood sampling collection tube having two oppositely positioned rubber stoppers sealing the corresponding oppositely positioned open ends of the said cylindrical tube, and interposed within the said tube is a slideable perpendicularly placed filtration disc that filters and separates the cellular elements of the whole blood from its fluid counterpart during the process of centrifugation. One embodiment of the tube having a special structural extension baffle at one of the two sealing rubber stoppers, said structural extension found proximal to the puncturable entrant area of the blood specimen into the tube, acts as the structural baffle that prevents or curtails hymolysis of the red blood cells during the sudden onrush of blood from the blood source through the bore of the collection needle, and into the vacuum of the said collection tube.