HydroLogix Tips (HLT) are designed to reduce sample retention. Molded from virgin polypropylene, they don?t use additives or coatings that may affect sample integrity. All sterile HLT tips are certified PURE. The testing protocols used in PURE certification are RNase and DNase Detection, Pyrogen Detection, Bioburden, PCR Inhibition, ATP Detection and Sterility Verification. All non-sterile products are certified DNA, RNase and DNase free.