A new independent study has demonstrated that Porvair Sciences’ pipette filter tips have greater than 99% Bacterial Filtration Efficiency (BFE) even at an increased challenge level. The test procedure was modified from a standard BFE procedure, based upon ASTM F2101, to employ a more severe challenge than would normally be experienced. For the testing, a suspension of Staphylococcus aureus, ATCC #6538, was delivered to the pipette filter tip at a challenge level of greater than 105 colony forming units. The challenge was aerosolised using a nebuliser and delivered to the pipette filter tip under tests at a fixed air pressure and flow rate of 5 l/min.
The aerosol droplets were generated in a glass aerosol chamber and drawn through the pipette filter tip into all glass impingers for collection. The challenge was delivered for a one-minute interval and sampling through the all-glass impingers was conducted for two minutes to clear the aerosol chamber. Across a sample set of 10 pipette filter tips the testing demonstrated a mean filtration efficiency of 99.36%. The pipette tip filters are fully compliant with FDA, USP Class VI and European Pharmacopoeia statutory regulations.