Celltreat Scientific Centrifuge Tubes - Offered in 15ml or 50mlCelltreat Scientific 15 & 50mL Centrifuge Tubes Graduations on clear tubes are printed in bold easy to read black ink and are accurate to 2% 50mL clear tubes include a black printed 50mL graduation line and 1, 2 and 3mL graduations molded into the conical bottom Large white marking area provides excellent contrast for identification All tubes are manufactured from high quality polypropylene and have smooth, flat surface polyethylene (HDPE) caps