Patent attributes
A cap which can form an essentially leak-proof seal with an open-ended vessel capable of receiving and holding fluid specimens or other materials for analysis. To minimize potentially contaminating contact between a fluid sample present in the vessel and humans or the environment, the cap has a frangible seal which is penetrable by a plastic pipette tip or other fluid transfer device. The cap further includes a filter for limiting dissemination of an aerosol or bubbles once the frangible seal has been pierced. The filter is positioned between the frangible seal and a retainer. The retainer is positioned on the cap above the filter and may be used to contain the filter within the cap. The material of the retainer may be penetrable by a fluid transfer device.