Unlike other filter types that contain additives that can inhibit enzymatic reactions, Rainin filtered pipette tips are made from pure virgin sintered polyethylene. Hydrophobic polyethylene particles prevent aerosols and liquids from being aspirated into the body of the pipette.
The filters are machine-loaded to assure that tips remain completely untouched during manufacturing and packaging. They are certified free of RNase, DNase, DNA, and pyrogen contamination. In addition, all filter tips are pre-sterilized by radiation after packaging as added protection for biological samples.