Non-self-sealing Filter tips

Filter tips are especially suited for working with PCR techniques, and fully meet the requirements for microbiology and radioisotope work. The integrated hydrophobic polyethylene filter serves as a barrier against aerosols formed during pipetting.
PLASTIBRAND® Filter tips protect the pipette shafts from contamination, and thus lessen the risk of cross-contamination and faulty measuring results.

The 0,5 - 10 µl, 2 - 20 µl and 50 - 1000 µl tips have graduations for a quick volume check.

PLASTIBRAND® filter tips are produced from colorless granules under the most stringent cleanroom conditions and are automatically racked. They are autoclavable at 121 °C (2 bar), acc. to DIN EN 285.

The disadvantages of self-sealing filter tips

Self-sealing filter tips have a PE filter that swells through possible additives on contact with liquids. This causes development of a barrier that should not let any liquid pass. Since this behavior is only initiated by diffusing liquids, a considerable part of the sample is already in the filter and cannot be recovered.
This is clearly a disadvantage with expensive, laboriously produced samples. In addition, additives in the polyethylene filter can contaminate the sample.

The advantages of non-self-sealing filter tips

Non-self-sealing filter tips have a PE filter that is free from chemical additives. Permeability is controlled by the combination of pore size and filter length, so that no aerosols can reach the pipette shaft. These filters function with consistent reliability.
On the other hand, liquids can pass very slowly should they accidentally contact the filter. Since the filter does not swell, the sample can be recovered from the filter by simply actuating the pipette's blow-out function, or by centrifugation if necessary.
This is clearly an important advantage of nonself- sealing filters, especially when working with valuable samples. As an added advantage, the absence of filter additives protects samples from this source of contamination.