Top-Line filter tips with very small pore filters are extremely important for applications such as PCR, sequencing, working with infectious and radioactive materials and biological work in which the test results can be affected by contamination. In the filter tips the best available material of polyethylene is included with the smallest pore size. As a result aerosol contamination is reliably prevented. The innovative filters with holds a sample that was accidentally sucked up too far, absolutely safe back. Unlike other filters with self-locking the sample can be easily released again and if necessary disposed.