Filter tips from various manufacturers were tested in a blind trial at the Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM) in Hanover, Germany. Testing focused on the prevention of pipette cone contamination by aerosols. Filter effect with regard to salt aerosols and biomolecules (DNA fragments) was examined. Quantitative determination of DNA fragments was performed using real-time PCR.The results indicate that ep Dualfilter T.I.P.S. are much better at protecting against aerosols than other commercially available filter tips. With regard to particle permeability (0.13 % +/- 0.11 %), ep Dualfilter T.I.P.S. are 55 to 677 times more effective than the filter tips tested from other manufacturers. ep Dualfilter T.I.P.S. were 21 to 600 times more effective when protection against DNA fragments was examined (0.02 % +/- 0.01 %). The worst measured results were for particle permeability 88.00 % +/- 7.00 % and for DNA permeability 12.00 % +/- 5.20 %. All filters of Eppendorf ep Dualfilter T.I.P.S., ep Dualfilter T.I.P.S. LoRetention and ep Dualfilter T.I.P.S. SealMax, are made of the same Polyethylene (PE) and have comparable pore size structure.For efficiency testing of filter tips no standardized test method exists. Thus a further study with ep Dualfilter T.I.P.S. SealMax was done based on the standard
EN 1822. This standard deals with filtration performance testing of filters as used, for example, for applications in clean room technology or pharmaceutical industry. The results of the filter efficiency testing done by a certified institute showed a minimum particle collection efficiency of the ep Dualfilter T.I.P:S. SealMax
of 99.5 % with NaCI aerosol particles sizes of 0.05 – 0.5 µm.All ep Dualfilter T.I.P.S. are sterilized by electron beams, certified pyrogen-free and PCR clean (free from human DNA, DNase, RNase and PCR-inhibiting substances).
