Capillary stop-flow junction having improved stability against accidental fluid flow
First Claim
1. In a device combination which comprises an electronic instrument and an analytical cartridge adapted to removably fit into said instrument for carrying out an analytical assay, wherein said cartridge comprises a housing containing a capillary stop-flow junction located at a junction where a capillary passageway used to transport a liquid in said housing enters a non-capillary internal chamber in said housing, an improvement which comprises:
- means for selectively trapping gas in said capillary passageway and non-capillary chamber, whereby when said means for trapping is activated and said liquid enters said capillary passageway, said gas is compressed by said liquid as said liquid flows through said capillary channel and said liquid stops flowing at said stop-flow junction, wherein said means for selectively trapping gas comprises an vent opening in said housing, a vent passageway connecting said chamber to atmosphere surrounding said cartridge at said vent, and a sealing member located externally to said housing which is capable of selectively closing said vent opening, wherein said sealing member is located in and operated by said electronic instrument.
5 Assignments
0 Petitions
Accused Products
Abstract
A capillary stop-flow junction located in a housing at an end of a capillary passageway used to transport a liquid and at the beginning of a non-capillary internal chamber in the housing, in which the stop-flow junction contains an improvement which comprises 1) means for selectively trapping a gas in the capillary passageway and non-capillary chamber, wherein when the means for trapping is activated and the liquid enters the capillary passageway, the gas is compressed by the liquid as the liquid flows through the capillary channel and stops flowing at the stop-flow junction; or 2) a stop-flow nozzle surrounding the capillary passageway and projecting into the chamber; or 3) the stop-flow junction being formed from a single housing body member; or 4) a rupture junction in the capillary pathway, wherein the rupture junction is a stop-flow junction providing less maximum available back pressure than the capillary stop-flow junction. Diluters capable of serial dilution that use the stop-flow junctions of the invention are also described.
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Citations
10 Claims
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1. In a device combination which comprises an electronic instrument and an analytical cartridge adapted to removably fit into said instrument for carrying out an analytical assay, wherein said cartridge comprises a housing containing a capillary stop-flow junction located at a junction where a capillary passageway used to transport a liquid in said housing enters a non-capillary internal chamber in said housing, an improvement which comprises:
means for selectively trapping gas in said capillary passageway and non-capillary chamber, whereby when said means for trapping is activated and said liquid enters said capillary passageway, said gas is compressed by said liquid as said liquid flows through said capillary channel and said liquid stops flowing at said stop-flow junction, wherein said means for selectively trapping gas comprises an vent opening in said housing, a vent passageway connecting said chamber to atmosphere surrounding said cartridge at said vent, and a sealing member located externally to said housing which is capable of selectively closing said vent opening, wherein said sealing member is located in and operated by said electronic instrument. - View Dependent Claims (2, 3, 4)
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5. A vent-assisted capillary stop-flow junction comprising a housing surrounded by a gaseous atmosphere and an electronic instrument into which said housing removably fits, wherein (1) said housing comprising:
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a. an internal chamber; b. liquid receiving means for accepting a liquid; c. a capillary channel connecting said liquid receiving means to said chamber; and d. a channel leading out of said chamber and connecting said chamber to the atmosphere and surrounding said housing; (2) said electronic instrument comprises means for selectively closing said channel and sealing said chamber from the atmosphere; wherein when (1) said means for selectively closing is activated and gas is trapped in said capillary passageway and said chamber and (2) said liquid is concurrently applied to said means for accepting a liquid, said liquid flows through said capillary channel, compresses air trapped in said housing by said means for trapping, and stops flowing at said stop-flow junction. - View Dependent Claims (6, 7, 8)
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9. A method for increasing stability of a capillary stop-flow junction in a housing surrounded by a gaseous atmosphere, which comprises the steps of:
- (1) providing a housing having;
i. an internal chamber of non-capillary dimensions; ii. liquid receiving means for accepting a liquid; iii. a capillary channel connecting said sample receiving means to said chamber; iv. said stop-flow junction at the intersection of said capillary channel and said chamber; and v. a venting channel leading out of said chamber and connecting said chamber to the atmosphere surrounding said housing; (2) inserting said housing into a device having means for selectively closing said venting channel and sealing said chamber from the atmosphere; and (3) closing said venting channel prior to applying said liquid to said means for accepting a liquid, whereby said liquid flows through said capillary channel and stops flowing at said stop-flow junction. - View Dependent Claims (10)
- (1) providing a housing having;
Specification