PCR tubes made of polypropylene with flat or domed hinged caps. Flat caps are either clear of frosted. Autoclavable and resist frezezing to -80 °C. Centrifugation to 20,000 G. All types are PCR Ready, free from: PCR inhibitors Human DNA RNase and DNase Pyrogens Endotoxins Heavy metals (acc. to EC/94/62)