Universal pipette and filter tips are manufactured of the highest grade resins. Every lot is tested and certified to be free of detectable Nuclease (Rnase/Dnase), Adenosine Tri-phosphate, and Endotoxin (pyrogen) contamination. All sterile products are irradiated electron beam radiation, which is same level as gamma irradiation but less harsh on plastics than radiation and does not leave toxic residues like gas sterilization usually does to the product.