Penetrable cap
View Patent ↗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.
1. A cap comprising:
a core structure comprising a closed side wall adapted to grip an open-ended vessel and having an opening formed therein; and
axially aligned first and second frangible seals affixed to the core structure, the first frangible seal being situated beneath the second frangible seal in a spaced-apart relationship and covering the opening in the core structure so as to provide a fluid barrier, wherein the first and second frangible seals are constructed and arranged to remain affixed to the core structure when penetrated by a fluid transfer.
2. The cap of claim 1 , wherein the core structure is a unitary plastic piece having a generally cylindrical shape.
3. The cap of claim 1 , wherein the first and second frangible seals are comprised of the same material.
4. The cap of claim 1 , wherein each of the first and second frangible seals comprises a foil or plastic film.
5. The cap of claim 4 , wherein each of the first and second frangible seals comprises the foil.
6. The cap of claim 5 , wherein each of the first and second frangible seals comprises a brittle layer.
7. The cap of claim 5 , wherein each of the first and second frangible seals comprises a foil layer, a heat seal layer and an intervening brittle layer.
8. The cap of claim 5 , wherein each of the first and second frangible seals comprises a foil layer and a combined brittle/heat seal layer.
9. The cap of claim 4 , wherein each of the first and second frangible seals comprises a plastic film.
10. The cap of claim 1 , wherein the first frangible seal is affixed to a top or bottom surface of a ledge extending inwardly from the closed side wall.
11. The cap of claim 10 , wherein the second frangible seal is affixed to a top surface of the closed side wall.
12. The cap of claim 1 , wherein the first frangible seal is affixed to a top surface of a ledge extending inwardly from the closed side wall or to a bottom surface of a skirt depending from the ledge.
13. The cap of claim 12 , wherein the second frangible seal is affixed to a top surface of the closed side wall.
14. The cap of claim 1 further comprising a filter interposed between the first and second frangible seals.
15. The cap of claim 14 , wherein the filter is comprised of a resilient material.
16. The cap of claim 14 , wherein the filter is constructed and arranged to facilitate the venting of air through the cap.
17. A closed system comprising the cap of any one of claims 1 - 16 in sealing engagement with an open-ended vessel adapted to hold a fluid substance.
18. A method for removing a fluid substance from the closed system of claim 17 , the method comprising the steps of:
(a) penetrating the first and second frangible seals with a fluid transfer device;
(b) drawing a fluid substance contained in the vessel into the fluid transer device; and
(c) removing the fluid transfer device from the closed system.
19. The method of claim 18 , wherein air passageways are formed between the fluid transfer device and the first and second frangible seals during the penetrating step.
20. The method of claim 19 , wherein the fluid transfer device is a plastic pipette tip.
21. The method of claim 18 further comprising the step of exposing the fluid substance removed in step (c) to reagents and conditions sufficient to amplify, a target nucleic acid sequence suspected of being contained in the fluid substance.