U.S. patent application number 14/852085 was filed with the patent office on 2016-04-07 for compositions, systems, and methods for immiscible fluid discrete volume manipulation.
The applicant listed for this patent is APPLIED BIOSYSTEMS, LLC. Invention is credited to David M. Cox, Ben Johnson, Linda G. Lee, Dennis Lehto, Peter Ma, Mark F. Oldham, Richard T. Reel, Sam L. Woo.
Application Number | 20160096153 14/852085 |
Document ID | / |
Family ID | 54203760 |
Filed Date | 2016-04-07 |
United States Patent
Application |
20160096153 |
Kind Code |
A1 |
Lee; Linda G. ; et
al. |
April 7, 2016 |
Compositions, Systems, And Methods For Immiscible Fluid Discrete
Volume Manipulation
Abstract
Systems and methods of manipulating discrete volumes of a first
fluid in a second fluid are provided. In some embodiments, discrete
volumes can be formed in a conduit. In other embodiments, addition
fluid can be added to a discrete volume in a first conduit by
injecting the addition fluid at a relatively higher pressure. In
some embodiments, discrete volumes that normally would not coalesce
can be manipulated to be merged together.
Inventors: |
Lee; Linda G.; (Palo Alto,
CA) ; Oldham; Mark F.; (Emerald Hills, CA) ;
Woo; Sam L.; (Redwood City, CA) ; Cox; David M.;
(Foster City, CA) ; Reel; Richard T.; (Hayward,
CA) ; Ma; Peter; (Cupertino, CA) ; Johnson;
Ben; (Palo Alto, CA) ; Lehto; Dennis; (Santa
Clara, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
APPLIED BIOSYSTEMS, LLC |
Carlsbad |
CA |
US |
|
|
Family ID: |
54203760 |
Appl. No.: |
14/852085 |
Filed: |
September 11, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12036037 |
Feb 22, 2008 |
9152150 |
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14852085 |
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60891225 |
Feb 22, 2007 |
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60891208 |
Feb 22, 2007 |
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Current U.S.
Class: |
73/61.44 ;
366/167.1 |
Current CPC
Class: |
B01L 3/0265 20130101;
B01L 2400/0481 20130101; G01N 2021/6439 20130101; B01L 2300/0816
20130101; G01N 21/6428 20130101; B01L 2200/0673 20130101; B01L
2300/0867 20130101; B01F 13/0071 20130101; G05D 7/0694 20130101;
G01N 35/08 20130101; B01F 3/0815 20130101; G01N 1/38 20130101; B01L
3/502784 20130101; B01F 3/0811 20130101; G01N 2001/386 20130101;
B01F 13/0076 20130101; B01L 3/502769 20130101; B01L 2200/06
20130101; B01L 2200/0605 20130101; G05D 11/131 20130101; B01F
5/0471 20130101; B01F 2003/0842 20130101; B01L 2400/0666 20130101;
B01F 13/0072 20130101 |
International
Class: |
B01F 3/08 20060101
B01F003/08; G01N 21/64 20060101 G01N021/64; G01N 35/08 20060101
G01N035/08; G05D 11/13 20060101 G05D011/13; B01F 5/04 20060101
B01F005/04 |
Claims
1.-15. (canceled)
16. A method of forming discrete volumes of a first fluid in a
second fluid wherein the first fluid and the second fluid are
immiscible with one another and the discrete volumes are spaced
apart from one another by the first fluid, the method comprising:
flowing the second fluid through a first conduit and to a junction
of the first conduit with a second conduit, the junction comprising
a fluid communication between the first conduit and the second
conduit; opening a valve in the second conduit, the valve
configured to assume an open position and a closed position and
comprising a distal surface, wherein the first conduit has an inner
sidewall and the distal surface is flush with the inner sidewall
when the valve is in the closed position; and injecting an amount
of first fluid from the second conduit and through the junction and
into the first conduit, while the valve is in the open position, to
form discrete volumes of the first fluid in the second fluid.
17. The method of claim 16, wherein the injecting comprises opening
a valve disposed in the second conduit.
18. The method of claim 16, wherein the injecting comprises
generating one or more bursts of pressure of at least about five
psi each, within a 100 millisecond period.
19. A method of coalescing a discrete volume of an addition fluid
with a discrete volume of a first fluid, comprising: flowing a
composition of fluids through a first conduit, the composition of
fluids comprising discrete volumes of a first fluid in a second
fluid, and a discrete volume of an addition fluid, the first fluid
and the second fluid being immiscible with one another, the
addition fluid and the second fluid being immiscible with one
another, the first fluid and the addition fluid being miscible with
one another, and the discrete volume of the first fluid and the
discrete volume of the addition fluid being spaced apart from one
another by a portion of the second fluid; positioning the portion
of the second fluid with a junction in the first conduit, the
junction comprising a second conduit in fluid communication with
the first conduit; and removing the portion of the second fluid at
the junction to coalesce the discrete volume of the first fluid
with the discrete volume of the addition fluid.
20. The method of claim 19, wherein the second fluid comprises a
non-fluorinated polyalkylpolysiloxane oil and the first fluid
comprises an aqueous fluid.
21. The method of claim 19, wherein the portion of the second fluid
is removed with a differential of about five psi or greater.
22. A method of detecting a discrete volume of a first fluid in a
second fluid, the first and second fluid being immiscible with each
other, the method comprising: adding a dye to the second fluid and
not to the first; sensing a first level of signal; and sensing a
second level of signal, wherein the second level is below a
predetermined threshold and the predetermined threshold is lower
than the first level, thereby detecting the presence of a discrete
volume of a first fluid in a second fluid.
23. The method of detecting of claim 22, wherein the dye is a
fluorescent dye.
24. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application which claims
priority to U.S. patent Ser. No. 12/036,037 filed Feb. 22, 2008,
which claims the benefit of priority under 35 U.S.C. .sctn.119(e)
to U.S. Provisional Patent Application Nos. 60/891,225, and
60/891,208 both of which were filed on Feb. 22, 2007, all of which
are incorporated herein by reference.
FIELD
[0002] The present teachings relate to methods of fluid
manipulation and systems and compositions for carrying out such
methods.
BACKGROUND
[0003] Discrete volumes of a first fluid separated from one another
by a second fluid that is immiscible with the first fluid, can
sometimes undesirably coalesce with one another. Efforts to prevent
such coalescence of discrete volumes can render the addition of a
miscible fluid to the discrete volumes unfeasible. It would be
desirable to prevent coalescence between two such adjacent
immiscible fluid discrete volumes yet permit the addition of a
third or addition fluid into one or both of the adjacent discrete
volumes.
SUMMARY
[0004] According to various embodiments, a system is provided that
comprises: a first conduit; a composition in the first conduit, the
composition comprising an oil and discrete volumes of an aqueous
fluid in the oil, the oil and the aqueous fluid being immiscible
with one another and the discrete volumes being spaced apart from
one another; a second conduit in fluid communication with the first
conduit, at a junction; a valve disposed along the second conduit;
and circuitry associated with the valve and configured to open the
valve when one of the discrete volumes is present at the
junction.
[0005] The pressurized addition of a miscible fluid (miscible with
the first fluid) from the second conduit into a junction of the
second conduit and the first conduit, where the composition
described above is present in the first conduit, can result at
least four outcomes, depending on the relative pressure difference
(in order of increasing relative pressure): 1) the miscible
addition fluid does not affect the passing discrete volume of first
fluid, but forms a separate discrete volume of addition fluid
either before or after the discrete volume of first fluid; 2) the
miscible addition fluid splits the passing discrete volume into at
least two smaller discrete volumes and forms a separate discrete
volume of addition fluid between the first and second smaller
discrete volumes of first fluid; 3) the miscible addition fluid
coalesces with the discrete volume of first fluid forming a larger
discrete volume of first and addition fluid; and 4) the miscible
addition fluid breaks the discrete volume of first fluid into
multiple small droplets, that do not coalesce. The boundaries of
differential pressures between these outcomes are not fixed but can
be affected by many variables, including at least the choice of
spacing fluid and surfactant and the diameters of the first and
second conduits.
[0006] The pressurized addition of the second fluid through the
second conduit into a junction of the second conduit and the first
conduit, where the composition described above is present in the
first conduit, can result at least four outcomes, depending on the
relative pressure difference (in order of increasing relative
pressure): 1) the pressurized second fluid does not affect the
passing discrete volume of first fluid, but increases the spacing
between the discrete volume of first fluid and one of its adjacent
discrete volumes in the composition; 2) the pressurized second
fluid splits the passing discrete volume into at least two smaller
discrete volumes spaced apart by second fluid; and 3) the
pressurized second fluid breaks the discrete volume of first fluid
into multiple small droplets, that do not coalesce.
[0007] In some embodiments, the valve can comprise a solenoid
valve. The valve can be configured to rest in a closed position,
and the valve can comprise a distal surface. The first conduit can
have an inner surface and when the valve is in the closed position
the distal surface of the valve can be flush with the inner surface
of the first conduit. The system can further comprise a pump
associated with the valve, and the circuitry is configured to
actuate the valve and power the pump. The valve and pump
combination can also be, for example, a metering pump, a piezo
pump, a solenoid squeezing a tube acting a pump, and an ink jet
pump.
[0008] According to various embodiments, a system is provided that
comprises: a first conduit; a composition in the first conduit, the
composition comprising an oil and discrete volumes of an aqueous
fluid in the oil, the oil and the aqueous fluid being immiscible
with one another and the discrete volumes being spaced apart from
one another; a second conduit in fluid communication with the first
conduit, at a junction; and a pump configured to pump a liquid
through the second conduit and configured to provide one or more
bursts of pressure within a 100 millisecond period. The pump can be
configured to force liquid out of the second conduit and into the
first conduit, at the junction, at a differentially higher pressure
sufficient to disrupt the stability of the discrete volume's
interface with the second fluid, allowing the forced liquid to
coalesce with the discrete volume.
[0009] According to various embodiments, a system is provided that
comprises: a first conduit; an oil in the first conduit; a second
conduit in fluid communication with the first conduit, at a
junction; an aqueous fluid in the second conduit, the oil and the
aqueous fluid being immiscible with one another; a valve disposed
along the second conduit; and a fluid movement system configured to
open the valve and force portions of the aqueous fluid from the
second conduit into the first conduit to form discrete volumes of
the aqueous fluid spaced apart from one another, in the oil. In
some embodiments, the first conduit can comprise a sidewall and the
junction can comprise a hole through the sidewall.
[0010] According to various embodiments, a method is provided that
comprises: flowing a composition of fluids through a first conduit,
the composition of fluids comprising discrete volumes of a first
fluid in a second fluid, the first fluid and the second fluid being
immiscible with one another and the discrete volumes being spaced
apart from one another by the first fluid; positioning a first
discrete volume of the discrete volumes with a junction in the
first conduit, the junction comprising a second conduit in fluid
communication with the first conduit; and injecting an amount of an
addition fluid from the second conduit into the junction at a
differentially higher pressure so that the amount of addition fluid
contacts and coalesces with the first discrete volume, the addition
fluid being miscible with the first fluid but non-coalesceable with
the first discrete volume if injected at a lower pressure. In some
embodiments, the composition of fluids can comprise a surface
active agent that is soluble in the first fluid and has a
hydrophilic/lipophilic balance of from about 2 to about 5. The
surface active agent can be present in the first fluid at a
concentration of from about 0.1% by weight to about 10% by weight,
based on the total weight of the first fluid and the surface active
agent. The second fluid can comprise a polysiloxane and the first
fluid can comprise an aqueous fluid. The surface active agent can
comprise a polyalkyleneoxide-substituted siloxane. In some
embodiments, the first fluid can comprise a polysiloxane and the
surface active agent can comprise a polyalkyleneoxide-substituted
polysiloxane. In some embodiments, the first fluid can comprise a
non-fluorinated polysiloxane oil. In some embodiments, the first
fluid can comprise a fluorinated oil.
[0011] According to various embodiments, a method is provided for
forming discrete volumes of a first fluid in a second fluid wherein
the first fluid and the second fluid are immiscible with one
another and the discrete volumes are spaced apart from one another
by the first fluid. The method can comprise: flowing the second
fluid through a first conduit and to a junction of the first
conduit with a second conduit, the junction comprising a fluid
communication between the first conduit and the second conduit;
opening a valve in the second conduit, the valve configured to
assume an open position and a closed position and comprising a
distal surface, wherein the first conduit has an inner sidewall and
the distal surface is flush with the inner sidewall when the valve
is in the closed position; and injecting an amount of first fluid
from the second conduit and through the junction and into the first
conduit, while the valve is in the open position, to form discrete
volumes of the first fluid in the second fluid. The composition of
fluids can comprise a surface active agent that is soluble in the
second fluid and has a hydrophilic/lipophilic balance of from about
2 to about 5. The surface active agent can be present in the second
fluid at a concentration of from about 0.1% by weight to about 10%
by weight, based on the total weight of the first fluid and the
surface active agent. In some embodiments, the second fluid can
comprise polysiloxane and the first fluid can comprise an aqueous
fluid.
[0012] According to various embodiments, a method of coalescing a
discrete volume of an addition fluid with a discrete volume of a
first fluid is provided. The method can comprise: flowing a
composition of fluids through a first conduit, the composition of
fluids comprising discrete volumes of a first fluid in a second
fluid, and a discrete volume of an addition fluid, the first fluid
and the second fluid being immiscible with one another, the
addition fluid and the second fluid being immiscible with one
another, the first fluid and the addition fluid being miscible with
one another, and the discrete volume of the first fluid and the
discrete volume of the addition fluid being spaced apart from one
another by a portion of the second fluid; positioning the portion
of the second fluid with a junction in the first conduit, the
junction comprising a second conduit in fluid communication with
the first conduit; and rapidly removing the portion of the second
fluid at the junction to coalesce the discrete volume of the first
fluid with the discrete volume of the addition fluid. In some
embodiments, the discrete volume of addition fluid and the discrete
volume of first fluid will not coalesce without the negatively
pressurized removal of the second fluid due to the presence of a
surface active agent in the second fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The skilled artisan will understand that the drawings
described below are for illustrative purposes only. The drawings
are not intended to limit the scope of the present teachings in any
way.
[0014] FIG. 1 is a cross-sectional view of a system and method for
carrying out a workflow according to various embodiments.
[0015] FIG. 2 is a cross-sectional view of a system and method for
carrying out a workflow according to various embodiments.
[0016] FIG. 3 is a cross-sectional view of a system and method for
carrying out a metered workflow according to various
embodiments.
[0017] FIG. 4 is a cross-sectional view of a system for carrying
out a metered workflow according to various embodiments.
[0018] FIG. 5 is a cross-sectional view of a system and method for
carrying out a variable metered workflow according to various
embodiments.
[0019] FIGS. 6-8 are schematic diagrams of three respective
processing systems according to various embodiments.
[0020] FIGS. 9 and 10 are schematic diagrams of two respective
processing systems according to various embodiments.
[0021] FIG. 11 is a technical drawing and specification sheet for
an exemplary valve that can be used according to various
embodiments.
[0022] FIG. 12 is a cross-sectional view of a system and method for
carrying out a workflow according to various embodiments.
[0023] FIG. 13 is cross-sectional view of a system and method for
detecting discrete volumes in a conduit.
DESCRIPTION
[0024] According to various embodiments, a composition is provided
that comprises an oil, for example, a non-fluorinated
polyalkylpolysiloxane oil, discrete volumes of an aqueous fluid in
the oil, and a surface active agent. The oil can comprise a
silicone oil, for example, a non-fluorinated polyalkylpolysiloxane
oil. The discrete volumes of aqueous fluid can be immiscible with
one another and the discrete volumes can be spaced apart from one
another with the oil in between. The composition can be provided in
a conduit having an inner diameter that is about equal to a
diameter of the discrete volumes of aqueous fluid, such that the
discrete volumes can be arranged in a single file from within the
conduit.
[0025] The surface active agent can be soluble in the oil and can
have a hydrophilic/lipophilic balance (HLB) of from about 1.0 to
about 8.0, from about 3.0 to about 6.0, for example, or from about
4.0 to about 5.0.
[0026] According to various embodiments, the surface active agent
can be present in the non-fluorinated, polyalkylpolysiloxane oil at
a concentration sufficient to prevent coalescence of the discrete
volumes with one another for a period of 48 hours, when kept at a
temperature in the range of about 0.degree. C. to about 40.degree.
C. In some embodiments, the surface active agent can be present in
the non-fluorinated, polyalkylpolysiloxane oil at a concentration
sufficient to prevent coalescence of the discrete volumes with one
another up to a temperature of at least 95.degree. C. In some
embodiments, the surface active agent can have an HLB and be
present in the non-fluorinated, polysiloxane oil at a concentration
that does not prevent coalescence of a discrete volume with a
proximate body of addition fluid that is miscible with the first
fluid of the discrete volume.
[0027] According to various embodiments, otherwise stable discrete
volumes (those that do not coalesce when in close proximity to one
another) can have their stability decreased through localized
temperature increases and therefore coalesce. The localized
temperature increase can be effectuated by resistive, microwave,
inductive coupling, or acoustic energy, for example.
[0028] According to various embodiments, the oil can comprise a
siloxane chain or ring according to the following structural
formulas:
##STR00001##
where R1, R2 can each an alkyl, aryl, vinyl, or trifluoropropyl; R3
can be an alkyl, hydroxyl, or acetyl; and n is within the range of
2-40 and m is within the range of 3-6.
[0029] According to various embodiments, the oil can comprise a
polysiloxane oil and the polysiloxane oil can comprise a di-, tri-,
tetra-, or penta-, siloxane. In some embodiments, the polysiloxane
oil can comprise a blend or mixture of two or more different oils.
In some embodiments, the polysiloxane oil can comprise a blend or
mixture of two or more polysiloxane oils. According to various
embodiments, the polysiloxane oil can have a viscosity ranging from
about 0.25 centistoke (cSt) to about 5.0 cSt, or from about 0.50
cSt to about 3.0 cSt, for example, from about 0.65 cSt to about 2.0
cSt.
[0030] According to various embodiments, the oil can comprise a
polysiloxane oil and the polysiloxane oil can comprise a
polydialkylcyclosiloxane or a blend of oils that comprises an
polydialkylcyclosiloxane. According to various embodiments, the
polydialkylcyclosiloxane can comprise a polydimethylcyclosiloxane.
According to various embodiments, the polydimethylcyclosiloxane can
comprise a decamethylcyclopentasiloxane.
[0031] According to various embodiments, the polysiloxane oil can
comprise polyalkylpolysiloxane. According to various embodiments,
the polyalkylpolysiloxane can comprise poly- methyl-, propyl-,
butyl-, pentyl-, hexyl-, octyl-, decyl-, polysiloxane. According to
various embodiments, the dimethylpolysiloxane can comprise a methyl
di-, tri-, tetra-, penta-, hexa-, octa-, deca-, siloxane.
[0032] In some embodiments, the composition can comprise a
polyalkylpolysiloxane oil having a viscosity of from about 0.25
centistoke to about 3.0 centistokes at 25.degree. C., for example,
from about 0.5 centistoke to about 2.0 centistokes at 25.degree. C.
In some embodiments, for example, an oil can be used that also
exhibits a viscosity in one or more of such ranges, at 90.degree.
C. The non-fluorinated, polyalkylpolysiloxane oil can, in some
embodiments, comprise one or more of an alkyldisiloxane oil, an
alkyltrisiloxane oil, and an alkyltetrasiloxane oil, and the alkyl
groups can comprise methyl, ethyl, propyl, and the like, alkyl
groups. In some embodiments, the oil can comprise a
polydimethylpolysiloxane such as decamethyltetrasiloxane. In some
embodiments, the oil can be non-fluorinated.
[0033] In some embodiments, the oil can comprise a mixture or blend
of two or more oils, for example, a mixture of a
polyalkylpolysiloxane oil and a polycyclosiloxane oil. An exemplary
mixture comprises a ten to one weight ratio of
decamethyltetrasiloxane to decamethylpentacyclosiloxane.
[0034] According to various embodiments, the surface active agent
can be provided as a polydialkylsiloxane-polyalkyleneoxide at a
concentration of from about 1.0% to about 20.0% by weight,
dispersed in an alkylcyclosiloxane. According to various
embodiments, the surface active agent can comprise about one
percent by weight solution of alkylsiloxane-polyalkyleneoxide
dispersed in a polysiloxane oil, which is then mixed with oil to
form the first fluid described herein. In some embodiments, the
surface active agent can comprise, for example, a detergent, a
wetting agent, or an emulsifier.
[0035] According to various embodiments, the surface active agent
can comprise a polyalkylene oxide. According to various
embodiments, the polyalkylene oxide can comprise a polyethylene
oxide (PEO) such as polyethylene glycol (PEG) or polypropylene
glycol (PPG).
[0036] According to various embodiments, the surface active agent
can comprise a backbone of polysiloxane, substituted with a
polyalkylene oxide. According to various embodiments, the
polysiloxane backbone can comprise a polyalkylsiloxane cross-linked
with a polyalkylene oxide that can form a gel particle of average
diameter ranging from about 1 micron to about 10 micron. According
to various embodiments, the average diameter of the gel particle is
about 5 microns.
[0037] According to various embodiments, the surface active agent
can comprise a polyalkyleneoxide-substituted siloxane, for example,
a polyethylene glycol-substituted siloxane. An exemplary surface
active agent is DC 9011 surfactant from Dow Corning. The surface
active agent can be dispersed in a carrier oil before it is mixed
with the oil described herein. For example, the surface active
agent can be dispersed in a polysiloxane oil or in a
polycyclosiloxane oil, before it is mixed with a
polyalkylpolysiloxane oil. In an exemplary embodiment, the surface
active agent can comprise a polyalkyleneoxide-substituted
polysiloxane dispersed in a cyclic polysiloxane oil, for example,
in D5, a decamethylpentacyclosiloxane oil.
[0038] According to various embodiments, the surface active agent
can comprise a silicone polyether, for example, PEG/PPG-18
dimethicone (10% by weight) in cyclopentasiloxane. An exemplary
surfactant of this type is SILSURF 400 R available from Siltech
Corporation of Toronto, Ontario, Canada Like other surface active
agents, SILSURF 400R can be provided as a dispersion in a carrier
oil, such as a polycyclosiloxane oil or
decamethylpentacyclosiloxane, for example, in a 10% by weight
dispersion, based on the total weight of the dispersion. The
carrier oil can be miscible with the oil used as the second fluid,
and can make up from about 1% to about 30% by weight of the total
weight of the oil, carrier oil, and surface active agent, combined,
for example, 10% by weight of such total weight.
[0039] Another exemplary surface active agent that can be used is
GRANSURF 77 available from Grant Industries, Elmwood Park, N.J.
GRANSURF 77 comprises PEG-10 dimethicone and can be provided neat
or in a dispersion, for example, in a dispersion comprising a
polycyclosiloxane oil.
[0040] The surface active agent can be provided in any suitable
concentration in an oil or oil mixture. Exemplary concentrations
can include, for example, about 0.1 to about 10% by weight surface
active agent based on the total weight of the combined surface
active agent and oil or oil blend. Concentrations of from about
0.25% by weight to about 5.0% by weight can be used, as can
concentrations of from about 0.5% by weight to about 3.0% by
weight, for example, about 1.0% by weight surface active agent.
[0041] According to various embodiments, the oil can comprise a
fluorinated oil and the surface active agent can comprise a
compound soluble in the fluorinated oil at a concentration
sufficient to prevent discrete volumes of aqueous fluid therein
from coalescing when in close proximity with each other, or in
other words, "touching".
[0042] According to various embodiments, a system is provided that
comprises: a first conduit; a composition in the first conduit, the
composition comprising an oil and discrete volumes of an aqueous
fluid in the oil, the oil and the aqueous fluid being immiscible
with one another and the discrete volumes being spaced apart from
one another; a second conduit in fluid communication with the first
conduit, at a junction; a valve disposed along the second conduit;
and circuitry associated with the valve and configured to open the
valve when one of the discrete volumes is present at the
junction.
[0043] In some embodiments, the valve can comprise a solenoid
valve. The valve can be configured to rest in a closed position,
and the valve can comprise a distal surface. The first conduit can
have an inner surface and when the valve is in the closed position
the distal surface of the valve can be flush with the inner surface
of the first conduit. The system can further comprise a pump
associated with the valve, and the circuitry is configured to
actuate the valve and power the pump. In some embodiments, the
circuitry can be programmed to actuate the valve, from a
non-actuated position, one or more times within a 100 millisecond
period, upon a triggering event. The triggering event comprises a
detection of one of the discrete volumes at or near the junction.
The circuitry can be programmed to actuate the valve for a period
of from about 0.1 millisecond to about 10 milliseconds, one or more
times within a 100 millisecond period. In some embodiments, the
valve can comprise an outlet port and the pump is configured to
force a liquid through the outlet port at a differentially higher
pressure of from about three psi to about 25 psi. In some
embodiments, the first conduit has an inner diameter of from about
0.010 to about 0.10 inch, the valve comprises an outlet port, and
the outlet port has inner diameter of from about 0.010 to about
0.10 inch.
[0044] According to various embodiments, a system is provided that
comprises: a first conduit; a composition in the first conduit, the
composition comprising an oil and discrete volumes of an aqueous
fluid in the oil, the oil and the aqueous fluid being immiscible
with one another and the discrete volumes being spaced apart from
one another; a second conduit in fluid communication with the first
conduit, at a junction; and a pump configured to pump a liquid
through the second conduit and configured to provide multiple
bursts of pressure within a 100 millisecond period. The pump can be
configured to force liquid out of the second conduit and into the
first conduit, at the junction, at a differentially higher pressure
of from about three psi to about 25 psi, for example, at a pressure
of from about three psi to about seven psi. The valve and pump
combination can also be, for example, a metering pump, a piezo
pump, a solenoid squeezing a tube acting a pump, and an ink jet
pump.
[0045] According to various embodiments, a system is provided that
comprises: a first conduit; an oil in the first conduit; a second
conduit in fluid communication with the first conduit, at a
junction; an aqueous fluid in the second conduit, the oil and the
aqueous fluid being immiscible with one another; a valve disposed
along the second conduit; and a fluid movement system configured to
open the valve and force portions of the aqueous fluid from the
second conduit into the first conduit to form discrete volumes of
the aqueous fluid spaced apart from one another, in the oil. In
some embodiments, the first conduit can comprise a sidewall and the
junction can comprise a hole through the sidewall. The fluid
movement system can comprise one or more pumps and at least one of
the one or more pumps can be configured to pump the aqueous fluid
through the second conduit at a predetermined rate. The valve can
be configured to be actuated for a period of time based on the rate
that the discrete volumes flow to provide discrete volumes of a
pre-selected volume. The valve can be opened for a timer period
depending on the input pressure, resistance to flow, and the
desired volume. The interval between valve openings then is the
rate at which discrete volumes are created. In some embodiments,
the first conduit can have an inner surface, the valve can comprise
a distal surface, and the distal surface of the valve can be flush
with the inner surface of the first conduit.
[0046] According to various embodiments, the circuitry can be
programmed to actuate the valve, from a non-actuated position, one
or more times within a 100 millisecond period. In some embodiments,
the rate of actuation can be slower and system throughput will be
reduced as a result. In some embodiments, the circuitry can be
programmed to actuate the valve for a period of from about 0.1
millisecond to about 10 milliseconds, one or more times within a
100 millisecond period. In some embodiments, the first conduit can
have an inner diameter of from about 0.010 to about 0.10 inch, the
valve can comprise an outlet port, and the outlet port can have an
inner diameter of from about 0.010 to about 0.10 inch.
[0047] According to various embodiments, a method is provided that
comprises: flowing a composition of fluids through a first conduit,
the composition of fluids comprising a first fluid and discrete
volumes of a second fluid in the first fluid, the first fluid and
the second fluid being immiscible with one another and the discrete
volumes being spaced apart from one another by the first fluid;
positioning a first discrete volume of the discrete volumes with a
junction in the first conduit, the junction comprising a second
conduit in fluid communication with the first conduit; and
injecting an amount of an addition fluid from the second conduit
into the junction at a sufficiently differentially higher pressure
so that the amount of addition fluid contacts and coalesces with
the first discrete volume, the addition fluid being miscible with
the second fluid but non-coalesceable with the first discrete
volume if injected at a lower pressure. In some embodiments, the
composition of fluids can comprise a surface active agent that is
soluble in the first fluid and has a hydrophilic/lipophilic balance
of from about 2 to about 5. The surface active agent can be present
in the first fluid at a concentration of from about 0.1% by weight
to about 10% by weight, based on the total weight of the first
fluid and the surface active agent. The first fluid can comprise
polysiloxane and the second fluid can comprise an aqueous fluid.
The surface active agent can comprise a
polyalkyleneoxide-substituted siloxane. In some embodiments, the
first fluid can comprise a polysiloxane and the surface active
agent can comprise a polyalkyleneoxide-substituted
polysiloxane.
[0048] In some embodiments, the second fluid can comprise an oil,
the first fluid can comprise an aqueous fluid, and the surface
active agent exhibits a hydrophilic/lipophilic balance of from
about 2 to about 5. The addition fluid can be injected from the
second conduit into the junction at a pressure of about five psi or
greater. The injecting can comprise opening a valve disposed in the
second conduit. In some embodiments, the injecting can comprise
generating single or multiple bursts of pressure within a 100
millisecond period. The injecting can comprise generating one or
more bursts of pressure of at least about five psi each, within a
100 millisecond period.
[0049] In some embodiments the flowing a composition of fluids can
comprise pushing the composition of fluids through the first
conduit. In some embodiments, the flowing a composition of fluids
can comprise pulling the composition of fluids through the first
conduit.
[0050] According to various embodiments, a method is provided for
forming discrete volumes of a first fluid in a second fluid wherein
the first fluid and the second fluid are immiscible with one
another and the discrete volumes are spaced apart from one another
by the first fluid. The method can comprise: flowing the second
fluid through a first conduit and to a junction of the first
conduit with a second conduit, the junction comprising a fluid
communication between the first conduit and the second conduit;
opening a valve in the second conduit, the valve configured to
assume an open position and a closed position and comprising a
distal surface, wherein the first conduit has an inner sidewall and
the distal surface is flush with the inner sidewall when the valve
is in the closed position; and injecting an amount of first fluid
from the second conduit and through the junction and into the first
conduit, while the valve is in the open position, to form discrete
volumes of the first fluid in the second fluid. The composition of
fluids can comprise a surface active agent that is soluble in the
second fluid and has a hydrophilic/lipophilic balance of from about
2 to about 5. The surface active agent can be present in the second
fluid at a concentration of from about 0.1% by weight to about 10%
by weight, based on the total weight of the second fluid and the
surface active agent. In some embodiments, the second fluid can
comprise polysiloxane and the first fluid can comprise an aqueous
fluid.
[0051] In some embodiments, the second fluid can be injected from
the second conduit into the junction at a pressure of about five
psi or greater. The injecting can comprise opening a valve disposed
in the second conduit. The injecting can comprise generating single
or multiple bursts of pressure within a 100 millisecond period. The
injecting can comprise generating one or more bursts of pressure of
at least about five psi each, within a 100 millisecond period.
[0052] According to various embodiments, a method of coalescing a
discrete volume of an addition fluid with a discrete volume of a
second fluid, is provided. The method can comprise: flowing a
composition of fluids through a first conduit, the composition of
fluids comprising discrete volumes of a first fluid in a second
fluid, and a discrete volume of an addition fluid, the first fluid
and the second fluid being immiscible with one another, the
addition fluid and the second fluid being immiscible with one
another, the first fluid and the addition fluid being miscible with
one another, and the discrete volume of the first fluid and the
discrete volume of the addition fluid being spaced apart from one
another by a portion of the first fluid; positioning the portion of
the second fluid in a junction in the first conduit, the junction
comprising a second conduit in fluid communication with the first
conduit; and removing the portion of the second fluid at the
junction to coalesce the discrete volume of the first fluid with
the discrete volume of the addition fluid.
[0053] According to various embodiments, the present teachings
relate to systems and methods of manipulating a composition that
comprises an oil, for example, a non-fluorinated
polyalkylpolysiloxane oil, discrete volumes of an aqueous fluid in
the oil, and a surface active agent. The oil can comprise a
silicone oil, for example, a non-fluorinated polyalkylpolysiloxane
oil. The discrete volumes of aqueous fluid can be immiscible with
one another and the discrete volumes can be spaced apart from one
another with the oil in between. In some embodiments, the
composition can be provided in a conduit having an inner diameter
that is about equal to a diameter of the discrete volumes of
aqueous fluid, such that the discrete volumes can be arranged in a
single file form within the conduit.
[0054] Referring now to the drawings and as shown in FIG. 1, the
system exemplified can comprise a first conduit 100 in fluid
communication with a second conduit 102 at a junction 104. A
composition comprising a non-fluorinated polyalkylpolysiloxane oil
106 and discrete volumes of aqueous fluid 108 travels through first
conduit 100 in the indicated direction. The non-fluorinated
polyalkylpolysiloxane oil 106 and the aqueous fluid 108 are
immiscible with one another and the discrete volumes of aqueous
fluid 108 are spaced apart from one another. An addition fluid 110
in second conduit 102 can be added to a discrete volume of aqueous
fluid 108 at the junction 104. According to various embodiments, a
constant stream of addition fluid 110 can be dispensed through the
second conduit 102. According to various embodiments, the addition
fluid 110 can be dispensed intermittently, periodically, or on
demand, through the second conduit 102. The volume flow of addition
fluid 110 can be controlled so as to dispense a desired volume of
addition fluid 110 at the junction 104 per unit of time.
[0055] The system can further comprise a pump 120 and a control
apparatus 122 configured to provide the addition fluid 110 to the
discrete volumes of aqueous fluid 108. Pump 120 and apparatus 122
can control the flow rate of addition fluid 110 so that a desired
amount of addition fluid can be added to each discrete volume of
aqueous fluid 108 at junction 104. Pump 120 and control unit 122
can be configured to pump addition fluid 110 continuously into
junction 104, intermittently into junction 104, periodically into
junction 104, or on demand into junction 104. In some embodiments,
pump 120 and control unit 122 can be configured to pump addition
fluid 110 continuously, at a low pressure, low flow rate punctuated
by pulses of high pressure. In some embodiments, a pump and control
unit can similarly be used to control the flow of non-fluorinated
polyalkylpolysiloxane oil 106 and discrete volumes of aqueous fluid
108 traveling through first conduit 100 by pushing the composition
in the direction indicated. In some embodiments, a pump and control
unit can similarly be used to control the flow of non-fluorinated
polyalkylpolysiloxane oil 106 and discrete volumes of aqueous fluid
108 traveling through first conduit 100 by pulling the composition
in the direction indicated.
[0056] In some embodiments, the discrete volumes of aqueous fluid
108 traveling through first conduit 100 may be unevenly spaced in
the polyalkylpolysiloxane oil 106. Consequently, the discrete
volumes of aqueous fluid 108 can potentially receive unintended
amounts of addition fluid 110 if the flow of addition fluid 110 was
to be continuous, and at a constant rate. For example, while some
discrete volumes of aqueous fluid 112 may receive the intended
amount of addition fluid 110, other discrete volumes such as 114
may receive less than the intended amount of fluid, and other
discrete volumes such as 116 may receive more than the intended
amount of addition fluid.
[0057] In the embodiment shown in FIG. 2, a first conduit 200 and a
second conduit 202 are in fluid communication with each other at a
junction 204. A composition comprising a non-fluorinated
polyalkylpolysiloxane oil 206 and discrete volumes of aqueous fluid
208 travels through the first conduit 200 in the direction
indicated. As a discrete volume of aqueous fluid 209 reaches
junction 204, a volume of non-fluorinated polyalkylpolysiloxane oil
210 can be injected into the composition through the second conduit
202. In various embodiments, the oil 210 can be injected with a
quick pulse or burst of sufficient pressure such that the discrete
volume of aqueous fluid 209 can be split into at least two discrete
volumes of aqueous fluid 212. In various embodiments, the
non-fluorinated polyalkylpolysiloxane oil 210 can be continuously
flowed through conduit 202 at a constant velocity into junction
204. In various embodiments, the flowrate of the non-fluorinated
polyalkylpolysiloxane oil 210 is sufficient to split the discrete
volume of aqueous fluid 209 into at least two discrete volumes of
aqueous fluid 212 as it passes through junction 204. A result of
continuously flowing the oil 210 into junction 204 is that the
spacing between discrete volumes of aqueous fluid is increased. In
various embodiments, the discrete volumes 212 comprise a pair of
nearly identical discrete volumes. The split discrete volumes of
aqueous fluid 212, 214, and 216 can remain non-coalesced as they
continue to travel through the first conduit 200.
[0058] In the embodiment shown in FIG. 2, a pump 220 and control
apparatus 222 can apply a positive pressure to second conduit 202
causing the addition of oil 210 through the second conduit 202. All
pressures are relative, for example, a partial vacuum could be
placed on the output of conduit 200.
[0059] In the embodiment shown in FIG. 3, a system is provided that
comprises a first conduit 300 and at least a pair of second
conduits 302A and 302B both in fluid communication with the first
conduit 300 at a junction 304A or 304B. A composition comprising a
non-fluorinated polyalkylpolysiloxane oil 306 and discrete volumes
of an aqueous fluid 308 travels through the first conduit 300 in
the indicated direction. As a discrete volume of aqueous fluid 308
travels through the first conduit 300 and past a junction 304A
and/or 304B, an addition fluid 310A and/or 310B can be injected
into the discrete volume 308, through the second conduit 302A
and/or 302B. The discrete volumes of aqueous fluid 312A and 312B,
314A and 314B, and 316A and 316B, comprising the addition fluid
310A and/or 310B, remain non-coalesced as they continue to travel
through the first conduit 300.
[0060] According to various embodiments, as shown in FIG. 3, the
system can comprise at least one valve 318A and 318B associated
with second conduits 302A and/or 302B and configured to control the
amount of addition fluid 310A and/or 310B flowing through second
conduits 302A and/or 302B. The valve 318A and/or 318B can be, for
example, a solenoid valve. The solenoid valve can be, for example,
a high-speed, two-way solenoid valve such as VHS SP INKX 0514950A
available from Lee Company, Essex, Conn. The valves can be
controlled by a valve control apparatus such as, for example, a
waveform generator. The wave form generator can be, for example, an
Agilent waveform generator, model number 33220A from Agilent
Technologies, Inc., Santa Clara, Calif. In some embodiments, the
solenoid valve can be controlled by a system controller.
[0061] According to the embodiment shown in FIG. 3, addition fluid
310A can be added, for example, to discrete volumes of aqueous
fluid 308 at the junction 304A, producing discrete volumes of
aqueous fluid 312A, 314A, and 316A. The addition fluid 310B can be
added, for example, to discrete volumes of aqueous fluid 308 at
junction 304B, producing discrete volumes of aqueous fluid 312B,
314B and 316B. According to various embodiments shown in FIG. 3,
both addition fluids 310A and 310B can be added to a single
discrete volume of aqueous fluid 308. According to various
embodiments, multiple second conduits 302, each with an addition
fluid 310, can be in fluid communication with the first conduit
300.
[0062] According to various embodiments, as shown in FIG. 3, the
system can comprise a sensor 324 for monitoring the composition in
the first conduit 300. Greater details about such sensors and their
components can be found, for example, in U.S. patent application
Ser. No. 11/508,756, filed on Aug. 22, 2006, which is incorporated
herein in its entirety by reference. The sensor 324 can detect and
monitor, for example, the discrete volumes of aqueous fluid 308
traveling through the first conduit 300. In various embodiments,
sensor 324 may detect a fluorescent dye in aqueous fluid 308.
[0063] The sensor 324 can be in communication with a pump 320 and a
control apparatus 322 to provide a metered addition of addition
fluid 310A and/or 310B to the discrete volumes of aqueous fluid
308. In some embodiments, there can be a pump for each valve. In
some embodiments, there can be one pump for all valves. All
possible combinations of number of valves associated with number of
pumps in between these two extremes can be incorporated. In the
embodiment shown in FIG. 3, the selection and addition of addition
fluid 310A and/or 310B can be keyed off the detection of a discrete
volume of aqueous fluid 308. Accordingly, any random spacing
existing between the discrete volumes of aqueous fluid 308 will not
affect the volume of addition fluid 310A and/or 310B, and the
additions to the discrete volumes 308 can be uniform and very
precise. In the embodiment shown in FIG. 3, the discrete volumes of
aqueous fluid with the added addition fluid 310A and/or 310B,
indicated as 312A, 312B, 314A, 314B, 316A and 316B, remain
non-coalesced as they continue to travel through the first conduit
300.
[0064] In one embodiment of the system represented in FIG. 3, the
addition fluid 310A and/or 310B can be, for example, different
sequencing primers such as reverse and/or forward sequencing
primers. An embodiment could comprise, for example, the system
shown in FIG. 2 whereby the discrete volume of aqueous fluid 208 is
split in half to form a pair of discrete volumes of aqueous fluid
212. The pairs of discrete volumes of aqueous fluid 212, 214, and
216 then continue to travel through the first conduit, feeding into
the system shown into FIG. 3. The pairs of discrete volumes of
aqueous fluid, now shown as 308 in FIG. 3, travel through the first
conduit 300 where reverse primer 310A or forward primer 310B can
then be added to alternate discrete volumes of aqueous fluid 312A
and 312B of the pair of discrete volumes 308. The addition of
forward and reverse primers can be performed sequentially or
simultaneously. In some embodiments, including those for use in
sequence detection applications, a larger number of junctions and
reagents can be incorporated in the system of FIG. 2.
[0065] As shown in FIG. 4, the system can further comprise a method
for tracking the discrete volumes of aqueous fluid 412-416 as they
travel through the conduit 400. The system can comprise the
addition of spectrally resolvable dyes to the discrete volumes. The
dyes can be added, for example, by including them in the addition
fluid 410A and/or 410B. A dye detection sensor 422 can be used to
detect the added dye as the discrete volumes 412-416 pass through
the conduit 400. The dyes can be, for example, at least two
different spectrally resolvable dyes emitting at different
wavelengths, or they can be, for example, two different
concentrations of the same dye. In various embodiments, the dye(s)
may be the same or different from the dye that may be already
present in discrete volumes of aqueous fluid 308. In some
embodiments, SYBR green can be added to the discrete volumes prior
to PCR, and can be detected using a blue light, for example, a blue
LED detection sensor (e.g., labeled SlugOmeter in FIGS. 6-8) to
trigger the addition of addition fluid and two concentrations of a
"red" dye can be used to distinguish the forward and reverse
reactions.
[0066] In the embodiment shown in FIG. 4, addition fluids 410A and
410B each contain a different concentration of the same fluorescent
dye. Accordingly, each discrete volume of aqueous fluids of the
pair of discrete volumes of aqueous fluid 412A, 412B, 414A, 414B,
and 416A, 416B is identified and tracked by one of the two
different concentrations of fluorescent dye. The different
concentrations of the same dye can provide resolvable threshold
values for identifying the contents of each individual discrete
volume. In the system shown in FIG. 4, forward and reverse
sequencing primers, for example, can be added with spectrally
resolvable dye in the addition fluid 410A and 410B. Accordingly,
the discrete volumes of aqueous fluid 412-416, comprising forward
or reverse sequencing reaction mixtures, can be identified and
monitored throughout the system.
[0067] In the embodiment found in FIG. 5, a system is provided that
comprises a first conduit 500 and a second conduit 502 in fluid
communication with the first conduit 500 at a junction 504. A
composition comprising a non-fluorinated polyalkylpolysiloxane oil
506 and discrete volumes of an aqueous fluid 508, 512, 514, and
516, travels through first conduit 500 in the indicated direction.
A pump 520 and a control apparatus 522 are configured to provide
the aqueous fluid 510 through the second conduit 502. A valve 530
and a valve control apparatus 532 are configured to control the
amount of aqueous fluid 510 in the discrete volume 508, and to
control the spacing between adjacent discrete volumes. The valve
530 can be, for example, a solenoid valve. The solenoid valve can
be, for example, a high-speed, two-way solenoid valve such as VHS
SP INKX 0514950A available from Lee Company, Essex, Conn. The valve
control apparatus 532 can be, for example, a waveform generator.
The waveform generator can be, for example, an Agilent waveform
generator, model number 33220A from Agilent Technologies, Inc.,
Santa Clara, Calif. The valve control apparatus 532 can be a system
controller.
[0068] In the embodiment shown in FIG. 5, the volume of the
discrete volume of aqueous fluid 512, 514, and 516, and the spacing
of the discrete volumes of aqueous fluid 512, 514, and 516 can be
controlled by varying the length of time and the intervals in which
the valve 530 is open. Further control of the volume and spacing
can be controlled by varying the pressure of the aqueous fluid 510
in the second conduit 502 and/or by varying the flow rate of the
oil 506 and resistance to flow in the second conduit 502. The
resistance to flow can be controlled by the size of the orifice of
the junction, or can be an orifice elsewhere, or can be provided by
the resistance to flow by a length of tubing. For example, the
aqueous fluid 510 can be pressurized with pump 520 and pump control
apparatus 522. According to various embodiments, the fluid can be
pressurized at a range of about 1 to 50 PSI, or at a range of about
1 to 10 PSI, for example, about 5 PSI. According to various
embodiments, the valve 530 can be set to remain open for a range of
about 0.1 to 10 ms, for example, 1 ms. According to various
embodiments, the valve 530 can be set to cycle about 1 to 100 times
within 100 ms, for example, 10 cycles. According to various
embodiments, the flow rate of polyalkylpolysiloxane oil 506 can be
controlled to flow at a rate of about 0.01 to 100 uL/s, for
example, about 0.75 uL/s. In some embodiments, multiple fluid
additions can be made to a single discrete volume from one addition
port.
[0069] As shown in FIG. 5, the volume and spacing of the discrete
volumes of aqueous fluid 512-516 can be controlled by varying the
parameters of pressure, oil flow rate, and pulse rate while keeping
the junction 504 size constant. According to the embodiment shown
in FIG. 5, the discrete volume size and spacing can be controlled
to produce discrete volumes of aqueous fluid 512, 514, and 516. The
discrete volumes of aqueous fluid 512-516 can remain non-coalesced
as they continue to travel through the first conduit 500. According
to the embodiment shown in FIG. 5, by controlling the parameters of
pressure, oil flow rate, and pulse rate, pulse duration, and flow
resistance, the discrete volume size and spacing can be reproduced
from instrument to instrument.
[0070] FIGS. 6, 7, and 8 depict various schematic diagrams of three
respective systems according to various embodiments. Greater
details about such systems and their components can be found, for
example, in each of U.S. patent application Ser. No. 11/507,735,
U.S. patent application Ser. No. 11/508,044, U.S. patent
application Ser. No. 11/508,756, and U.S. patent application Ser.
No. 11/507,733, all filed on Aug. 22, 2006, which are incorporated
herein in their entireties by reference. Greater details about
systems and methods for fluid manipulation that can be used in
conjunction with the teachings herein, can also be found in
concurrently filed U.S. Provisional Patent Application No.
60/891,208 entitled "Non Continuous Addition of Fluid to Immiscible
Fluid Discrete Volumes Using an Electric Field" to Woo et al.
(attorney docket number 6754P), which is incorporated herein in its
entirety by reference.
[0071] In the schematic diagrams of FIGS. 6-8, the detector system
(labeled SlugOmeter in the diagrams) can be the same as the various
detectors shown and described in U.S. patent application Ser. No.
11/507,735, U.S. patent application Ser. No. 11/508,044, U.S.
patent application Ser. No. 11/508,756, and U.S. patent application
Ser. No. 11/507,733. The Big Dye/FWD primer refers to dye
terminator sequencing reagents wherein each of the
dideoxynucleotide chain-terminators can be labeled with a separate
fluorescent dye which fluoresces at a different wavelength, for
example, the BigDye.RTM. Terminator v3.1 and v1.1 product family
available from Applied Biosystems, Foster City, Calif. Primer A and
Primer B can be different sequencing primers known in the art, for
example, forward primers, reverse primers, and zip code primers.
Primer A and Primer B can be real time PCR primers known in the
art, for example, cDNA primers and SNP primers. ExoSAP refers to a
reagent for PCR clean-up prior to downstream sequencing comprising
two enzymes, Exonucleose I and shrimp alkaline phosphatase. ExoSAP
can be utilized to remove unwanted dNTPs, residual primers, and
extraneous single stranded DNA from the PCR mixture.
[0072] FIGS. 9 and 10 depict various schematic diagrams of two
respective systems according to various embodiments. In the system
shown in FIG. 9, a sample in the form of a discrete volume, and at
least one primer in the form of a discrete volume, can be separated
by oil and can then be merged together by removing the oil between
them. By suctioning off the oil that otherwise would space the
sample discrete volume and the primer discrete volume apart, the
two discrete volumes can be made to coalesce. The surge of pressure
differential can be of sufficient force to cause the sample
discrete volume and the primer discrete volume to merge together
and coalesce even when they would not coalesce when in close
proximity in the absence of such a pressure differential surge. The
pressure differential can be of any adequate value to enable
coalescence of the two discrete volumes. Exemplary pressure
differentials can include differentials of from about 3 psi to
about 25 psi, for example, from about 4 psi to about 10 psi or
about 5 psi. Greater ranges of pressures will work with different
diameter tubing and changes to flow resistance, among other
variables.
[0073] In the system shown in FIG. 10, a sample in the form of a
discrete volume, and at least one primer in the form of a discrete
volume, can be separated by oil and can then be merged together by
injecting and addition fluid, such as a master mix (for example,
PCR master mix available from Applied Biosystems, Foster City,
Calif.), between the two discrete volumes. The addition fluid can
be miscible with both the sample discrete volume and the primer
discrete volume. By injecting the addition fluid with a pressure
differential surge between the two adjacent discrete volumes, oil
that otherwise would space the sample discrete volume and the
primer discrete volume apart is forced out of the way such that the
two discrete volumes and the addition fluid can be made to
coalesce. The surge of pressure differential can be of sufficient
force to cause the sample discrete volume, the primer discrete
volume, and the addition fluid to merge together and coalesce even
when they would not coalesce when in close proximity in the absence
of such a pressure differential surge. Several additions can be
made at intervals, so that precise positioning of volume/precise
time of the addition does not increase the success of the addition.
The pressure differential can be of any adequate value to enable
coalescence of the two discrete volumes with the addition fluid.
Exemplary pressure differentials can include differentials of from
about 3 psi to about 25 psi, for example, from about 4 psi to about
10 psi or about 5 psi. Valves, pumps, sizes, burst parameters, and
circuitry, and control systems that can be used for controlling
such injection can include those described herein, for example, in
connection with the embodiments shown in FIGS. 3 and 4.
[0074] FIG. 11 is a technical drawing and specification sheet for
an exemplary valve that can be used according to various
embodiments.
[0075] FIG. 12 is a cross-sectional view of a system and method for
splitting a discrete volume and the pressurized addition of a first
reagent to the first half of the split discrete volume and the
pressurized addition of a second reagent to the second half of the
split discrete volume. Discrete volumes of an aqueous fluid are
separated by an oil with a soluble surfactant therein, with which
the aqueous fluid is immiscible. The discrete volumes 1, 2, and 3
are not uniformly spaced in the conduit. Another conduit
continuously and uniformly flows more oil with surfactant into a
junction of that conduit and the conduit containing the series of
discrete volumes 1, 2, and 3. As the discrete volumes pass through
the junction, the flow of oil with surfactant splits them into to
smaller discrete volumes. In some embodiments, and as illustrated
in FIG. 12, the uniform addition of oil with surfactant can split
discrete volume 1 into two approximately equal halves, 1a and 1b,
each a smaller discrete volume containing approximately have the
volume of the original discrete volume 1. The same process occurs
with discrete volumes 2 and 3, as illustrated to the right of the
junction (before is illustrated to the left of the junction, after
is illustrated to the right of the junction). The relevant
parameters to affect whether the discrete volume is split into two,
three, or more smaller discrete volumes and the relative volumes of
the smaller discrete volumes can include the flow rate of the
composition of discrete volumes of aqueous fluid separated by oil
with surfactant and the size of the discrete volumes 1, 2, and
3.
[0076] Still in reference to FIG. 12, after splitting the discrete
volumes 3 into smaller discrete volumes 3a, 3b, a discrete volume
detection sensor shown below the conduit detects the presence
and/or the length of smaller discrete volume 3a, and provides the
information to a system controller (not shown) that predicts the
time that smaller discrete volume 3a will be positioned under the
forward primer conduit, so as to control the actuation of the valve
and release of pressurized forward primer, which will coalesce with
smaller discrete volume 3a. The system controller can also
calculate the time that smaller discrete volume 3b will be
positioned under the reverse primer conduit, so as to control the
actuation of the valve and release of pressurized reverse primer,
which will coalesce with smaller discrete volume 3b. The locations
of the conduits for the forward and reverse primer reagents can be
fixed as a function of the expected spacing of the smaller discrete
volumes 3a and 3b with the uniform addition of oil with surfactant
at a predetermined flow rate. The valves are opened for a
predetermined time to allow metered amounts to be added to
alternated discrete volumes 3a and 3b. In the embodiment
illustrated in FIG. 12, random spacing of discrete volumes 1, 2,
and 3 will not affect the volume of addition.
[0077] FIG. 13 illustrates another system and method of detecting
discrete volumes of a first fluid separated by a second fluid with
which the first fluid is immiscible. As illustrated in FIG. 13, a
dye that is soluble in the second fluid is added to the second
fluid. That dye is not added to the first fluid. Therefore, a
detector that detects the presence of the dye in the second fluid
will sense a signal as shown in the graph: A constant higher value,
with short pulses of a lower signal. In some embodiments, the dye
can be colorimetric. In some embodiments, the dye can be
fluorescent. Detection of the discrete volumes, as, for example,
discussed in regard to FIG. 12, can use this "negative" or reduced
signal to time subsequent additions of fluid that is miscible with
the first fluid. In some embodiments where the second fluid is oil,
exemplary dyes that can be used as described above include copper
or aluminum phthalocyanine. Nile Red, for example, produced by
Sigma Aldrich, dissolves in silicone oils and emits yellow light
(about 560 nm) when irradiated with blue light.
[0078] In some embodiments, including the resequencing (or variable
input) workflow, Nile Red cam be used in the oil phase. A blue LED
detection sensor can be used for all detection sensors (labeled
SlugOmeter and illustrated with a triangle in FIGS. 6 and 7) in all
locations except the last one. Triggering off of the negative
signal can permit timed addition of exoSAP, and later the
sequencing terminators, (e.g., labeled "Big Dye/FWD primer A in
FIG. 7). In some embodiments, the forward primer can have a first
concentration of red dye and the reverse primer can have a second
concentration of red dye, where the first and second concentrations
are resolvable. Exemplary red dyes are FMAT blue from Applied
Biosystems, and Cy5 from Invitrogen. In some embodiments, including
those using the different concentrations of red dye in the forward
and reverse primer, a "red" LED detection sensor can be used at the
depositing ("spit") end of a microfluidic device to track the
forward and reverse reactions.
[0079] Other embodiments of the present teachings will be apparent
to those skilled in the art from consideration of the present
specification and practice of the present teachings disclosed
herein. It is intended that the specification and examples be
considered as exemplary only and not be limiting. All cited
references, patents, and patent applications are incorporated in
their entireties herein by reference.
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