US 5,104,813 AGranted

Dilution and mixing cartridge

AssigneeBiotrack, Inc.

InventorsDon Besemer, Michael Gorin, Ian Gibbons

Life of this patent

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Abstract

A dilution and mixing cartridge is provided that allows single (or multiple) dilutions of a sample with a diluent in a disposable cartridge in which a measurement, such as optical density, is made. Addition of sample to the device automatically measures the sample, and addition of diluent automatically causes a fixed ratio of sample and diluent to enter a receiving chamber, in which mixing and measurement can take place. A number of preferred embodiments are provided in which the diluent application site is located at a vertical height below the sample application site, flow directing chambers are provided to control flow of desired volumes of sample or diluted sample at the appropriate locations in the device and to direct excess sample and diluent to waste locations, or control mechanism are provided at flow directing chambers and other internal locations to verify correct operation of the device.

Claims44

Dependent claims

A dilution and mixing cartridge for automatically measuring and diluting a liquid sample with a liquid diluent, comprising:

in a housing,
sample receiving means for receiving a sample,
a flow directing chamber, comprising a first internal chamber in said housing,
sample flow means for delivering sample from said sample receiving means to said flow directing chamber,
diluent receiving means for receiving a diluent,
diluent flow means for delivering diluent from said diluent receiving means to said flow directing chamber,
a receiving chamber, comprising a first vented internal chamber in said housing having a first volume,
a measuring chamber, comprising a second internal chamber in said housing having a second volume smaller than said first volume, wherein said measuring chamber connects said flow directing chamber to said receiving chamber and said measuring chamber is capable of delivering sample and diluent from said flow directing chamber to said receiving chamber solely by capillary and gravitational forces,
a stop flow junction located at the end of said measuring chamber, wherein said stop flow junction with conforms to the surface tension characteristics of said sample so as to provide sufficient back pressure resulting from contact between said sample and wall means of said housing at said stop flow junction to prevent sample from flowing through said stop flow junction in absence of diluent but allowing flow through said stop flow junction when said diluent receiving means receives diluent and diluent enters said flow directing chamber, and
waste means for emptying said flow directing chamber after sample has entered said flow directing chamber and said sample has filled said measuring chamber, wherein said waste means operates by capillary and gravitational forces,
whereby diluent added to said diluent receiving means flows through said flow directing chamber and expels sample from said measuring chamber into said receiving chamber, thereby causing a fixed ratio of sample to diluent to be delivered to said receiving chamber.

8 more elements

A method for diluting a liquid sample with a liquid diluent, comprising:

sequentially supplying an unmeasured volume of said sample and a measured or unmeasured volume of said diluent to a liquid flow directing chamber, wherein (1) a first portion of said sample entering said flow directing chamber is diverted to a measuring chamber having a first volume, flow of sample through said measuring chamber terminating when said sample reaches a stop flow junction, said stop flow junction conforming to the surface tension characteristics of said sample so as to provide sufficient back pressure resulting from contact between said sample and wall means of said housing at said stop flow junction to prevent sample from flowing through said stop flow junction, the remainder of said sample being diverted by said flow directing chamber to a waste chamber, and (2) a first portion of said diluent entering said flow directing chamber is diverted to said measuring chamber, wherein hydrostatic pressure from said diluent expels said sample in said measuring chamber into a receiving chamber along with said first portion of said diluent, whereby a fixed ratio of sample to diluent is delivered to said receiving chamber.

Dependencies are inferred from the claim text.

Facts

Application: 07/337,286Filed 13 Apr 1989
Granted: 14 Apr 1992
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G01N 1/38
Preparing specimens for investigation including physical details of chemical methods covered elsewhere, e.g. G01N33/50, C12Q: diluting, dispersing…
B01L 3/5027
With fluid transport, e.g. in multi-compartment structures: by integrated microfluidic structures, i.e. dimensions of channels and chambers are…
B01L 3/502723
By integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g.…
G01N 33/04
Food: dairy products