The centrifuge tube is made of high-purity PP material, , no pyrogen, no DNAs/RNase, autoclavable at 121°C/370°F, freezer to -80°C/-230°F. The transparent exterior with high visibility allows you to easily view the samples inside, the 50ml centrifuge tubes are sterile with easy-to-read black scales from 5.0ml to 50ml in 2.5ml increments. The centrifuge tube also includes a large white writing area for easy marking and identification. The patches are great for marking, and the graduations and writing area are chlorine . The centrifuge tube design has a longer screw cap with a sealing ring to prevent leakage. The lid can be tightly screwed onto the centrifuge tube, which has excellent sealing performance and effectively prevents liquid leakage. Smooth and flat inner , no residue solution. These centrifuge tubes are widely used in biochemistry and molecular biology, pharmacy and chemical laboratories, clinical diagnostic experiments, food science, etc. Color: As Shown Material: PP Package Contents: 4 set x 25 pieces test tubes with lids Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.