... 50ml centrifuge tube (2)with printed graduation (3)with u-shape bottom (4)ISO 9001:2000 Centrifuge TubeThis centrifuge tube ... can keep shape and good seal.The bottom is u-shape .U-shape bottom,screw cap,with printed graduation,autoclavable, ... cap,No-sterile,Bulk PackPP100pcs/polybag,1000pcs/cartonMCT-50ml-u-bBule cap,No-sterile,Bulk PackPP100pcs/polybag,1000pcs/cartonSterile ...