The unique design of tube cover thread makes single-hand holding easy and passed strict leakage tests. The cover can bear -90Kpa/cm and has the features of no leakage, no deformation and no tube burst. Provide individual package according to users’ needs; 15ml maximum centrifugal force: 15000xg, 50ml centrifugal force: 12000xg; Range of tolerable temperature: -80℃-121℃; DNase/RNase-free, non pyrogenic, non-cytotoxic; The products have passed strict leakage tests. The tube has smooth surface and uniform color and is sterilized through irradiation.