Useful for collecting and transporting biological specimens. Leakproof characteristics are ensured by a flat top plastic screw cap with an inner sealing lip. Molded graduations from 2.5 to 50ml. Can be autoclaved and will resist temperatures up to 121C. They will also resist acids, solvents and alkalies at room temperature. They withstand centrifugation speeds of 3000 g or 5000 RPM. Polypropylene tubes only can be autoclaved and resist acids, solvents and alkalies.- 50mL Centrifuge Tube, Sterile, Polystyrene, Green Cap, 25/rack, 20 rack/cs