A new independent study demonstrates Porvair Sciences' pipette filter tips have greater than 99% bacterial filtration efficiency (BFE) even at an increased challenge level.
The independent test procedure employed was modified from a standard BFE procedure, based upon ASTM F2101, in order to employ a more severe challenge than would be experienced in normal use.
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 litres per minute. 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 filters tips the testing demonstrated a mean filtration efficiency of 99.36%. All testing was performed in compliance with US FDA good manufacturing practice (GMP) regulations 21 CFR Parts 210, 211 and 820.