Centrifuge Tubes Oil fully graduated are used to contain liquids during centrifugation, which separates the sample into its components by rapidly rotating it around a fixed axis. Most centrifuge tubes have conical bottoms, which help collect any solid or heavier parts of the sample being centrifuged. graduated, Suitable for SolubilityTest, Conical Bottom, Graduated, Cap : 50 ml, Length: 120 -125 mmDia.30 mm with Graduation Mark 0-1 ml, 0.1ml, 1-2 ml, 0.2 ml,2-10 ml, 0.5 ml, 10-20 ml, 1 ml & at 50 ml