Corning 15 mL clear polypropylene (PP) centrifuge tubes come with the advanced polyethylene CentriStar caps and are bulk packed 50 per bag. Foam racks can be purchased separately. The CentriStar Cap has a easy-on/easy-off flat top and offers advanced ergonomics with its wider knurls and roll-over edge design for easier gripping. This leak-proof design comes with a revolutionary plug feature that virtually eliminates all seepage when used under recommended conditions. Superior Performance Maximum RCF is 12,500 xg Temperature range from -80°C to 120°C 5 year shelf life Ease of Use Leak proof design Easy-on/easy-off cap Clear accurate graduations Large white marking spot Reliable Quality RNase-/DNase-free Heavy-metal-free color concentrate Medical grade polypropylene Nonpyrogenic Sterile -MOHON TANYAKAN STOCKNYA TERLEBIH DAHULU