Pestles in G-Tubes®Pestles in G Tubes These disposable polypropylene pestles can be used to gently release sperm from testicular material. All the packaging options contain products free of detectable RNase, DNase, DNA and Pyrogens. These pestles and tubes are precision manufactured and quality controlled to firmly match together for maximum performance efficiency. Pestles are conveniently packaged into the appropriate size tubes, ready for use and are sterilized.