Patent ID: 7691332

Claim:
A penetrable cap comprising: a core structure comprising: a closed side wall; a ledge extending radially inwardly from an inner surface of the side wall, the ledge defining an opening that is sized to receive a pipette tip therethrough; a first bore defined by the inner surface of the side wall and a top surface of the ledge, the first bore extending from the top surface of the ledge to a top surface of the side wall; and attachment means for fixing the cap to an open end of a vessel in sealing engagement; a first frangible seal comprising a foil layer, the first frangible seal being affixed to a surface of the ledge to provide a fluid barrier between the first bore and fluid contents of a vessel; and a second frangible seal affixed to a top surface of the side wall, the second frangible seal being disposed over the first bore and in axial alignment with the first frangible seal, wherein the cap is capable of being penetrated by a plastic pipette tip, and wherein the cap is capable of being penetrated by a plastic pipette tip, and wherein air passageways are formed between the first and second frangible seals and a plastic pipette tip when the plastic pipette tip penetrates the first and second frangible seals, whereby air can be vented through the cap when the cap is secured to an open end of a vessel.