The MTC Bio P3040 PureAmp Individual PCR Tubes, 0.2mL, Attached Dome Caps, Pack of 1000, are precision manufactured to maintain tight dimensional tolerances of ultra-thin wall thickness, resulting in improved thermal transfer. The PureAmp PCR Plastics are certified free of RNase, DNase, DNA and PCR inhibitors, and are made of heat resistant medical-grade polypropylene.