U.S. patent application number 15/094751 was filed with the patent office on 2016-10-13 for fluid addition to immiscible fluid discrete volumes using an electric field.
The applicant listed for this patent is APPLIED BIOSYSTEMS, LLC. Invention is credited to David M. Cox, Richard T. Reel, Sam L. Woo.
Application Number | 20160296896 15/094751 |
Document ID | / |
Family ID | 54203760 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160296896 |
Kind Code |
A1 |
Reel; Richard T. ; et
al. |
October 13, 2016 |
Fluid Addition To Immiscible Fluid Discrete Volumes Using An
Electric Field
Abstract
Compositions are provided comprising a first fluid, in the form
of discrete volumes, wherein the discrete volumes are spaced apart
from one another by a second fluid that is immiscible with the
first fluid. According to various embodiments, the composition can
comprise a surface active agent, for example, a surfactant, that
lowers, minimizes, and/or eliminates coalescence between two
adjacent discrete volumes of the first fluid, in the absence of an
applied electric potential or field. In some embodiments, the first
fluid can comprise an aqueous solution, for example, containing
biological material and/or reagents, and the second fluid can
comprise an oil. Systems are also provided that can comprise a
conduit system for flowing compositions such as those described
above, and circuitry configured to supply an electric potential
and/or electric field at, near, and/or adjacent, a junction in the
conduit system. The electrical potential, and/or electric field
generated thereby, can be matched to the coalescence properties of
the composition such that, when applied, an addition fluid
continuously flowed into a junction with the composition can be
added directly to a discrete volume of the composition as it passes
through the junction. Methods using the compositions and systems
are also provided.
Inventors: |
Reel; Richard T.; (Hayward,
CA) ; Cox; David M.; (Foster City, CA) ; Woo;
Sam L.; (Redwood City, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
APPLIED BIOSYSTEMS, LLC |
Carlsbad |
CA |
US |
|
|
Family ID: |
54203760 |
Appl. No.: |
15/094751 |
Filed: |
April 8, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12036069 |
Feb 22, 2008 |
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15094751 |
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60891211 |
Feb 22, 2007 |
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60891225 |
Feb 22, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01F 13/0071 20130101;
B01L 3/0265 20130101; G01N 2021/6439 20130101; G05D 11/131
20130101; G01N 35/08 20130101; B01F 3/0815 20130101; B01F 13/0072
20130101; B01L 3/502769 20130101; B01L 2300/0867 20130101; G05D
7/0694 20130101; G01N 1/38 20130101; B01F 13/0076 20130101; B01L
2400/0666 20130101; B01L 2200/0605 20130101; B01L 3/502784
20130101; B01L 2300/0816 20130101; B01F 2003/0842 20130101; B01L
2200/06 20130101; B01F 5/0471 20130101; G01N 2001/386 20130101;
B01F 3/0811 20130101; B01L 2200/0673 20130101; G01N 21/6428
20130101; B01L 2400/0481 20130101 |
International
Class: |
B01F 3/08 20060101
B01F003/08; G01N 1/38 20060101 G01N001/38; B01F 13/00 20060101
B01F013/00; B01L 3/00 20060101 B01L003/00 |
Claims
1-10. (canceled)
11. A method of coalescing an addition fluid with a discrete volume
of a second fluid, comprising: flowing a composition of fluids
through a first conduit, the composition of fluids comprising
discrete volumes of a first fluid in the 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
second fluid; positioning a first discrete volume of the discrete
volumes in a junction in the first conduit, the junction comprising
a second conduit in fluid communication with the first conduit;
flowing a body of addition fluid through the second conduit and
into the junction so that a portion of the body of addition fluid
contacts the first discrete volume, the addition fluid being
miscible with the first fluid but non-coalesceable with the first
discrete volume in the absence of an applied electric field; and
applying an electric field to the junction to cause the portion of
the body of addition fluid to coalesce with the first discrete
volume at the junction.
12. The method of claim 11, wherein the composition of fluids
comprises a surface active agent that is soluble in the second
fluid and has a hydrophilic/lipophilic balance of from about 2 to
about 7.
13. The method of claim 12, wherein the surface active agent is
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 surface active agent.
14. The method of claim 11, wherein the second fluid comprises a
non-fluorinated polyalkylpolysiloxane oil and the first fluid
comprises an aqueous fluid.
15. The method of claim 11, wherein the surface active agent
comprises a polyalkyleneoxide-substituted siloxane.
16. The method of claim 11, wherein the surface active agent
comprises a polyethylene glycol-substituted siloxane.
17. The method of claim 11, wherein the second fluid comprises a
non-fluorinated polyalkylpolysiloxane oil and the surface active
agent comprises a polyalkyleneoxide-substituted polysiloxane.
18. The method of claim 11, wherein the second fluid comprises an
oil, the second fluid comprises an aqueous fluid.
19. The method of claim 11, wherein the applying an electric field
comprises applying an electric potential of at least about 5.0
volts, alternating current, at a frequency of at least about 4.0
kHz, at the junction.
20. The method of claim 11, wherein the applying an electric field
comprises applying an electric potential to an electrode sleeve
surrounding a portion of the second conduit at the junction.
21. The method of claim 11, further comprising continuously pushing
the addition fluid through the second conduit and into the
junction.
22. The method of claim 11, wherein the applying an electric field
comprises applying an electric potential of at least about 5.0
volts alternating current at a frequency of from about 4.0 kHz to
about 50.0 kHz.
23. The method of claim 11, wherein the first fluid comprises a
silicone oil, the surface active agent comprises a polyalkylene
oxide-substituted polysiloxane, and the applying an electric field
comprises applying an electric potential of at least about 5.0
volts alternating current at a frequency of at least about 1.0 kHz.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/036,069 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 60/891,211,
which were filed on Feb. 22, 2007, and are explicitly incorporated
in their entireties by reference herein.
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
another miscible fluid into one or both of the adjacent discrete
volumes.
SUMMARY
[0004] The present teachings relate to compositions of a first
fluid, in the form of discrete volumes, wherein the discrete
volumes are spaced apart from one another by a second fluid that is
immiscible with the first fluid. According to various embodiments,
the composition can comprise a surface active agent, for example, a
surfactant, that lowers, minimizes, and/or eliminates coalescence
between two adjacent discrete volumes of the first fluid in the
absence of an applied electric potential or field. In some
embodiments, the first fluid can comprise an aqueous solution, for
example, containing biological material and/or reagents, and the
second fluid can comprise an oil.
[0005] According to various embodiments, a system can be provided
that can comprise a conduit system for flowing compositions such as
those described above, and circuitry configured to supply an
electric potential and/or electric field at, near, and/or adjacent,
a junction in the conduit system. The electrical potential, and/or
electric field generated thereby, can be matched to the coalescence
properties of the composition such that, when applied, a
predetermined volume of a body of addition fluid being introduced
into the junction through another conduit of the conduit system can
be made to flow directly into the discrete volume of the first
fluid, thereby making a larger discrete volume of first and
addition fluid. All other things being constant, if the electric
potential, and/or electric field, generated thereby are absent, the
volume of addition fluid introduced to the junction will form a
separate, discrete volume of addition fluid near or next to the
discrete volume of the first fluid, without coalescing, as the
composition flows through the junction.
[0006] According to various embodiments, a method is provided
whereby miscible fluid discrete volumes of a first fluid, separated
from one another by a second fluid that is immiscible with the
first fluid, can be flowed through a conduit and to a junction. A
third fluid that is miscible with the first fluid can be added to a
discrete volume of the first fluid at the junction. According to
various embodiments, the method can comprise applying an electric
potential and/or field at or near the junction to facilitate
coalesceability of the miscible addition fluid with a first fluid
discrete volume at the junction. In some embodiments, the junction
can comprise an intersection between a first conduit and an
addition-fluid supply conduit. The addition fluid can be supplied
to the junction through the addition-fluid supply conduit. The
addition fluid provided at the junction can separate from the body
of addition fluid in the addition-fluid supply conduit and join, or
in other words, coalesce with one or more first fluid discrete
volumes at the junction, without forming a separate discrete volume
as an intermediate step.
[0007] According to various embodiments, a method can be provided
whereby a minimum electrical potential can be matched to a
composition comprising a surfactant such that a discrete volume of
the first fluid in the composition does not coalesce with another
miscible fluid present at a junction in the absence of the
electrical potential but does coalesce with a volume of a miscible
addition fluid when at least the minimum electrical potential is
applied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] 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. In the drawings:
[0009] FIG. 1 is a cross-sectional view of a system for carrying
out a single molecule workflow according to various
embodiments;
[0010] FIG. 2 is a cross-sectional view of a system for carrying
out a variable input workflow according to various embodiments;
[0011] FIGS. 3A and 3B are cross-sectional close-up views of a
system comprising a junction, and electrical circuitry for
providing an electric field at the junction;
[0012] FIGS. 4 and 5 are schematic diagrams of two respective
processing systems according to various embodiments;
[0013] FIGS. 6-8 depict the formulae of three different surface
active agents that can be used in compositions according to various
embodiments;
[0014] FIG. 9 is a cross-sectional close-up view of a system
comprising a junction, and electrical circuitry for providing an
electric field at the junction;
[0015] FIG. 10 is a cross-sectional close-up view of a system
comprising a junction, and electrical circuitry for providing an
electric potential near the junction; and
[0016] FIGS. 11-15 depict various systems and methods according to
various embodiments for five respective different processing
methods.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0017] 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.
[0018] 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.
[0019] 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 in the absence of an applied electric
potential 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 in the absence of an applied electric potential 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 in the presence of an applied electric potential,
for example, an applied electric potential of from about 5.0 volts
to about 20 volts, AC, at about 0.1 kHz frequency or higher. The
voltage can be applied at any suitable frequency, for example, at a
frequency of at least about 1.0 kHz, at a frequency of from about
1.0 kHz to about 100 kHz, at a frequency higher than 100 kHz, or at
a frequency of at least about 4.0 kHz. In some embodiments, a
balance between HLB and concentration can be used to formulate a
composition that maintains discrete volumes of a fluid, for
example, discrete volumes of an aqueous fluid, that are in
proximity to each other, separate and distinct from each other
without coalescing, at least in the absence of a sufficiently large
applied electric field, wherein the discrete volumes of such
composition do coalesce with each other when in close proximity,
upon application of an appropriate electric field at the interfaces
thereof.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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-, pent-, hexa-, octa-, deca-, siloxane.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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).
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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. In
some embodiments, greater concentrations of surface active agent
can be used with higher applied electric potentials, relative to
the electric potential that can be used with lower concentrations
of surface active agent.
[0033] 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 in the absence of an applied electric field.
[0034] According to various embodiments, a system is provided that
comprises: a first conduit; a composition as described above, in
the first conduit; a second conduit in fluid communication with the
first conduit at a junction; and electric circuitry configured to
apply an electric potential and/or field at the junction. An
addition fluid can be present in the second conduit, and the
addition fluid can be miscible with the aqueous fluid and
non-coalesceable with the discrete volumes in the absence of the
electric potential. The electric circuitry can be configured to
apply an electric potential of at least about 1.0 volt, for
example, at least about 5.0 volts, alternating current, at the
junction. The voltage can be applied at a frequency of at least
about 0.1 kHz, for example, at least about 1.0 kHz. An exemplary
frequency can be, for example, at least about 4.0 kHz. In an
exemplary embodiment, the electric circuitry can be configured to
apply an electric potential of from about 5.0 volts to about 20
volts alternating current at a frequency of from about 4.0 kHz to
about 50 kHz, to form an electric field at the junction.
[0035] The electric circuitry can comprise an electrode that
contacts the second conduit, for example, an electrode sleeve
surrounding a portion of the second conduit at the junction. The
first conduit can comprise a portion upstream of the junction and a
portion downstream of the junction, and the electric circuitry can
comprise at least a first electrode disposed along the portion of
the first conduit upstream of the junction, downstream of the
junction, and/or at the junction. The electric circuitry can also
comprise at least a second electrode disposed along the second
conduit. In some embodiments, each of the first conduit and the
second conduit can comprise an outer surface comprising an
electrically insulating material, for example, a plastic material.
In some embodiments, the first electrode can be in contact with the
outer surface of the first conduit while the second electrode can
be in contact with the outer surface of the second conduit. In some
embodiments, the conduits can comprise a polyolefin, such as
polyethylene or polypropylene, a fluoropolymer such as
polytetrafluoroethylene (PTFE), or a polyethyleneterephthalate
(PET). Other materials that can be used for the conduits include
perfluoroalkoxy-2 (PFA), fluorinated ethylene propylene (FEP),
polyvinylidene fluoride (PVDF, e.g., KYNAR.TM.), and
ethylenetetrafluoroethylene (ETFE, e.g., TEFZEL.TM.). In various
embodiments, the fluidic pathways can be present between layers,
such as those milled or molded on a chip.
[0036] According to various embodiments, the system can comprise a
pump configured to move a composition including immiscible fluid
discrete volumes along the first conduit from upstream of the
junction to downstream of the junction. In some embodiments, the
pump can cause a negative pressure from a downstream side of the
junction to pull fluids through the first conduit, and in some
embodiments, the pump can cause a positive pressure from an
upstream side of the junction to push fluids through the first
conduit. Positive pressures of from about 2 psig to about 20 psig,
for example, from about 8 psig to about 12 psig, can be used
according to various embodiments. In some embodiments, pressure is
used to reduce expansion of aqueous discrete volumes during
heating, for example, during heating to temperatures needed for
polymerase chain reaction, and in some embodiments, to temperatures
from about 94.degree. C. to about 96.degree. C.
[0037] According to various embodiments, a system is provided that
comprises: a first conduit comprising an outer surface that
comprises an electrically insulating material; a second conduit in
fluid communication with the first conduit, at a junction, the
second conduit comprising an outer surface that comprises an
electrically insulating material, wherein the first conduit
comprises a portion upstream of the junction and a portion
downstream of the junction; and electric circuitry comprising at
least a first electrode disposed along the first conduit and at
least a second electrode disposed along the second conduit.
Although the portions of the first conduit upstream and downstream
of the junction can comprise separate, different conduits, the
portions are nonetheless together referred to herein as portions of
the first conduit. In some embodiments the first electrode can be
disposed along the portion of the first conduit upstream of the
junction. In some embodiments the first electrode can be disposed
along the portion of the first conduit downstream of the junction.
In some embodiments the first electrode can be disposed along the
first conduit at the junction. According to various embodiments,
either or both conduits can comprise an electrically conductive
material can be used, for example, a carbon-filled plastic
material.
[0038] In some embodiments, the first electrode can be in contact
with the outer surface of the first conduit, and the second
electrode can be in contact with the outer surface of the second
conduit. The electrodes do not need to penetrate the conduits and
contact liquid inside the conduits but can instead be clamped to,
or otherwise in contact with, the outer surface of each conduit. In
some embodiments the electric circuitry can comprise an electrode
sleeve surrounding a portion of the second conduit at the junction.
In some embodiments, the electric circuitry can be configured to
apply an electric potential of from about 1.0 volt to about 100
volts alternating current, for example from about 5.0 volts to
about 20 volts. The voltage can be applied, for example, at a
frequency of from about 1.0 kHz to about 100.0 kHz, for example, at
from about 5 kHz to about 50 kHz, or at, at least about 4 kHz.
[0039] In some embodiments, the electric circuitry can be
configured to apply an electric potential of from about 5.0 volts
to about 20.0 volts alternating current, for example, at a
frequency of at least about 1.0 kHz. The electric circuitry can
apply alternating current of any of a variety of waveforms, for
example, the alternating current can be in the form of a sine wave,
a square wave, a pulsed wave, a ramp wave, an arbitrary wave, a
saw-tooth wave, or the like.
[0040] According to various embodiments, a method of fluid addition
is provided whereby an addition fluid can be made to coalesce with
a discrete volume of a first fluid. 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. The first fluid and the second fluid can be
immiscible with one another and the discrete volumes can be spaced
apart from one another by the second fluid. The method can comprise
positioning a first of the discrete volumes at a junction along the
first conduit, wherein the junction comprises an intersection of a
second, or addition, conduit that is in fluid communication with
the first conduit. The method can further comprise flowing a
continuous supply of the third (addition) fluid, in contrast to a
second composition of discrete volumes of the addition fluid in the
second fluid, through the second conduit and into the junction so
that a portion of the continuous supply of addition fluid contacts
the first discrete volume. The third fluid can be miscible with the
first fluid but non-coalesceable with the first discrete volume in
the absence of an applied electric field. The method can also
comprise applying an electric field to the junction to cause the
portion of the continuous supply of third fluid to coalesce with
the first discrete volume at the junction, yet to not cause the
first discrete volume to coalesce with its adjacent discrete
volumes in the composition.
[0041] The method can comprise continuously flowing the body of
third fluid, which fills the addition-fluid supply conduit, into
the junction at a constant rate. The method can comprise flowing
the body of third fluid, which fills the addition-fluid supply
conduit, periodically, intermittently, in a pulsed fashion, or in a
like manner into the junction.
[0042] In some embodiments, detection of discrete volumes reaching
the junction can be used to determine and/or adjust the flow of
third fluid through the second conduit and to the junction.
[0043] In some embodiments, the method can process a composition of
fluids that comprises a surface active agent that is soluble in the
second fluid and that has a hydrophilic/lipophilic balance of from
about 2 to about 8, for example, from about 3 to about 7 or from
about 4 to about 5. In some embodiments where the volume of the
discrete volumes before addition is within the range of about 100
nanoliters to about 1000 nanoliters, the surface active agent used
according to the method 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 second and surface active
agent. Discrete volumes having volumes in the 10 picoliter to 10s
of nanoliters may use a lower concentration of surface active agent
to prevent coalescence with each other in the absence of an applied
electric field. The surface active agent can, for example, have a
hydrophilic/lipophilic balance that does not prevent coalescence of
the discrete volume with an addition fluid in the presence of an
applied electric potential yet which does prevent coalescence in
the absence of an applied electric potential. An exemplary applied
electric potential, that can be used, for example, as an exemplary
threshold value, can be at least about 5.0 volts alternating
current at a frequency of at least about 1.0 kHz, for example, 7.5
volts square wave alternating current at a frequency of 4 kHz.
[0044] The method can involve the use of a first fluid that
comprises an aqueous fluid. The method can involve the use of a
second fluid that comprises a non-fluorinated polyalkylpolysiloxane
oil. In some embodiments, the third fluid, which is to be added to
selected discrete volumes of the first fluid, can comprise an
aqueous fluid, for example, aqueous-based polymerase chain reaction
reagent or reagent mixture. In some embodiments, the third fluid
can comprise an aqueous-based sequencing reaction reagent or
reagent mixture, for example, a mixture of reagents to carry out a
forward or reverse Sanger cycle sequencing reaction. In some
embodiments, the third fluid can comprise aqueous-based PCR
amplification clean-up compounds, e.g., exo-SAP. In some
embodiments, the method involves the use of a surface active agent
that comprises a polyalkyleneoxide-substituted siloxane, for
example, a polyethylene glycol-substituted siloxane. In some
embodiments, the first fluid can comprise a non-fluorinated
polyalkylpolysiloxane oil, and the surface active agent can
comprise a polyalkyleneoxide-substituted polysiloxane. According to
various embodiments of the method, the first fluid can comprise an
oil, the second fluid can comprise an aqueous fluid, and the
surface active agent can be one that exhibits a
hydrophilic/lipophilic balance of from about 1 to about 7, or from
about 3 to about 6, or from about 4 to about 5.
[0045] In some embodiments, the method can comprise applying an
electric potential of at least about 1.0 volt, alternating current,
at the junction, for example, at least about 5.0 volts. The method
can comprise applying voltage at a frequency of at least about 1.0
kHz, at the junction, for example, at a frequency of at least about
4 kHz, or from about 1.0 kHz to about 100 kHz.
[0046] In some embodiments, electric circuitry can be provided that
generates an electric field encompassing the junction. The electric
field can be generated by applying an electric potential of at
least about 1.0 volt alternating current (AC). Exemplary potentials
comprise the ranges of from about 1.0 volt to about 100 volts, from
about 5.0 volts to about 50 volts, and from about 15 volts to about
20 volts, for a system comprising, for example,
polytetrafluoroethylene conduits having a 0.035 inch outer
diameters and 0.024 inch inner diameters, and a composition that
comprises discrete volumes flowing through the conduits each having
a diameter that about equals the inner diameters of the conduits.
Such exemplary potentials can be applied by placing the two
electrodes each about two inches away from the junction, for
example, the first electrode contacting the first conduit
downstream of the junction, and the second electrode contacting the
second or addition conduit. Other spacings away from the junction
can be used instead, for example, spacings of from about 0.1 inch
to about 10 inches away from the junction can be used to position
the electrodes relative to the junction. The spacing can be in any
radial direction away from the junction, for example, in directions
along the respective conduits. In some embodiments, a first
electrode contacts the addition conduit along the addition conduit
and about one to five inches away from the junction, and another
electrode floats, in effect being coupled to the first conduit
through the capacitive effects of the air, etc. Other diameters for
the conduits can also be used, for example, conduits having from
about 0.001 to about 0.2 inch inner and outer diameters, or from
about 0.005 inch to about 0.1 inch inner diameters and from about
0.010 inch to about 0.015 inch outer diameters.
[0047] According to various embodiments, the discrete volumes
traveling through the first conduit, before and/or after a junction
along the first conduit, can be oblong in shape and can have, for
example, a cross-sectional shape that generally matches and can be
defined by the cross-sectional shape of the inside of the first
conduit. For example, in embodiments where the first conduit has a
circular inner cross-section, each discrete volume traveling
through the first conduit likewise has a circular cross-section of
just slightly smaller dimension than the dimension of the conduit
inner cross-section. While the diameter of each discrete volume
will always be less than the inner diameter of the first conduit
through which the discrete volume is moving, the diameter of each
discrete volume can be more than 75% of the inner diameter of the
first conduit, for example, greater than 80%, greater than 85%,
greater than 90%, or greater than 95% of the inner diameter of the
first conduit. In some embodiments, each discrete volume can have a
cross-sectional diameter that is from about 95% to about 99.9% of
the inner diameter of the conduit in which the discrete volumes are
disposed. In some embodiments, the shape of each discrete volume in
the first conduit can be oblong such that each discrete volume has
an axial dimension. The leading and trailing faces of each discrete
volume can comprise curved surfaces, for example, hemispherical
surfaces, and a middle portion of each discrete volume can have a
cylindrical shape when traveling through a straight portion of the
first conduit. According to various embodiments, the axial
dimension of each discrete volume can be less than or greater than
the cross-sectional dimension thereof. In some embodiments, when
greater, the axial dimension of each discrete volume can be from
about 110% to about 1000% the cross-sectional diameter of each
discrete volume, for example, from about 150% to about 750%, or
from about 200% to about 500%. Although the discrete volumes will
take-on a cross-sectional shape that roughly matches the
cross-sectional shape of the first conduit through which they are
traveling, surface tension in aqueous discrete volumes tend to
cause the discrete volumes to take on rounded surfaces as opposed
to sharp, angular corners, even when traveling through a first
conduit with a square cross-section.
[0048] According to various embodiments, each discrete volume can
have an axial length that is less than the diameter of the discrete
volume. In such cases, the axial dimension can be measured from the
front or leading face of the discrete volume to the back or
trailing face of the discrete volume. The axial dimension can be
collinear with the axial dimension of the first conduit. In some
embodiments, the axial dimension can be from about 30% to about
100% of the diameter of each discrete volume, for example, from
about 50% to about 90% or from about 60% to about 80% of the
diameter.
[0049] In some embodiments, discrete volumes that are to be
processed according to various embodiments of the present teachings
can comprise volumes of liquid within the range of from about 100
nanoliters (nL) to about 100 microliters (.mu.L), depending upon
the inner diameter of the first conduit through which discrete
volumes are made to travel. In some embodiments, for tubing having
an inner diameter of 0.024 inch, the discrete volumes to be
processed at a junction can enter the junction having volumes of
from about 200 nL to about 2000 nL, each, for example, from about
300 nL to about 1000 nL or from about 400 nL to about 500 nL, each.
In some embodiments, larger discrete volumes of, for example, from
about 1000 nL to about 2000 nL can be split by introducing oil into
the discrete volumes at a junction, as described herein, to provide
smaller discrete volumes of from about 200 nL to about 500 nL,
each, for example, of about 400 nL each.
[0050] Other combinations of temperature, voltages, frequencies,
tubing material, diameters, vicinities of electrodes to the
junction, and sizes and shapes of the discrete volumes, can be used
to provide a system that enables the application of an electric
field of sufficient strength and vicinity to cause addition fluid
flowing into a junction to coalesce with a first discrete volume
and yet not cause electrocoalesence of the first discrete volume
and its adjacent discrete volumes.
[0051] According to various embodiments of the method, the first
conduit can comprise a portion upstream of the junction and a
portion downstream of the junction, and the method can comprise
applying an electric potential to a first electrode disposed along
the portion of the first conduit downstream of the junction. In
some embodiments, the method can comprise applying potential to a
second electrode disposed along the second conduit. In some
embodiments, the method can comprise applying an electric potential
to an electrode sleeve surrounding a portion of the second or
addition conduit, at the junction. The electrode sleeve can
comprise, for example, a metal sleeve or a sleeve made out of any
other electrically conductive material. The sleeve can comprise
copper, aluminum, stainless steel, brass, nickel, platinum,
palladium, combinations thereof, and the like. The sleeve can have
an inner diameter that about equals or is only slightly larger than
the outer diameter of the conduit around which the sleeve is
disposed. In some embodiments, the sleeve has an inner diameter
that is from about 1.0 micron to about 1.0 millimeter larger than
the outer diameter of the conduit around which the sleeve is
disposed. In some embodiments, both the first and second electrodes
can comprise a sleeve.
[0052] In some embodiments, the method can comprise applying
electric potential to each of the first conduit and the second
conduit, wherein each conduit comprises an outer surface comprising
an electrically insulating material. In some embodiments, the
entire conduit can comprise the same material. In some embodiments,
the conduits can comprise plastic tubing, for example,
polytetrafluoroethylene tubing. The method can comprise contacting
the outer surface of the first conduit with the first electrode and
contacting the second electrode with the outer surface of the
second conduit.
[0053] In some embodiments, the method can comprise flowing fluids
through one or more of the conduits by pushing the fluids, for
example, pushing the fluids through the first conduit and through
the addition conduit. The system can comprise one or more pumps and
an appropriate control system for controlling flow rate, pressure,
and/or other parameters that involve the movement of the
composition of discrete volumes of a first fluid in a second fluid
through the system. Likewise, the system can comprise one or more
pumps and an appropriate control system for controlling flow rate,
pressure, and/or other parameters that involve the movement of
addition fluid through a second or addition conduit of the
system.
[0054] The method can comprise pulling a composition of fluids
through the first conduit, for example, a composition comprising
discrete volumes of a first fluid in a second fluid, wherein the
first and second fluids are immiscible with respect to one another.
The method can further comprise pushing a third fluid through the
second conduit and into the junction, for example, by
intermittently, periodically, independently, or on demand, pushing
a volume of the third fluid through the second conduit, through the
junction, and into the first conduit. Even spacing between discrete
volumes traveling through the first conduit and into the junction
can be used to provide additions of equal volume to each of the
discrete volumes, if the discrete volumes pass the junction at a
constant rate. For example, 100 nanoliter-sized portions of the
third fluid can be added to each of a plurality of 500
nanoliter-sized discrete volumes of the first fluid.
[0055] In some embodiments, the method can comprise continuously
feeding or pumping addition fluid, as opposed to intermittently,
through the second conduit and through the junction, into the first
conduit. If continuously fed, the third (addition) fluid can be fed
at a constant flow rate through the addition conduit and into the
first conduit. The continuous flow can be of sufficient volume,
relative to the flow of discrete volumes through the first conduit,
to provide additions, each of a volume that about equals from about
1% to about 50% of the volume of a respective discrete volume to
which the addition is to be made, for example, the flow rate of the
addition fluid can be such that each addition is of a volume equal
to about 20% of the volume of the respective discrete volume to
which the addition is to be made.
[0056] In some embodiments, even spacing between discrete volumes
traveling through the first conduit and into the junction can be
provided, facilitating the addition of equal volumes to the
discrete volumes. In some embodiments, the portions of the third
fluid to be added to discrete volumes at the junction can be from
about 1% by volume to about 50% by volume of the size of the
discrete volumes to which the third fluid is to be added, for
example, from about 5% by volume to about 40% by volume, or from
about 10% to about 30% by volume. In some embodiments, about a 100
nanoliter-sized portion of third fluid can be added to a 500
nanoliter-sized discrete volume. In another example, portions of
third fluid can be added to 500 nanoliter-sized discrete volumes,
and the addition fluid portions can be from about 50 nanoliters to
about 200 nanoliters, or from about 75 nanoliters to about 150
nanoliters.
[0057] Other methods of pushing and pulling fluids into and through
a junction are described, for example, in greater detail 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.
[0058] In some embodiments, the method can comprise applying an
electric potential, for example, an electric potential of at least
about 5.0 volts alternating current, for example, from about 5.0
volts to about 20 volts alternating current. The voltage can be
applied at a frequency of at least about 1.0 kHz, for example, at a
frequency of from about 1.0 kHz to about 100.0 kHz.
[0059] According to various embodiments, the second fluid can
comprise a silicone oil, the surface active agent comprises a
polyalkylene oxide-substituted polysiloxane, and the method can
comprise applying an electric potential of at least about 5.0 volts
alternating current at a frequency of at least about 1.0 kHz, for
example, applying a potential of about 17 volts AC at a frequency
of about 4.0 kHz to two polytetrafluoroethylene conduits (the first
conduit of dimensions 0.035 inch outer diameter and 0.024 inch
inner diameter, and the addition conduit of 381 microns inner
diameter and 813 microns outer diameter), by contacting the
conduits with respective electrodes each spaced two inches away
from the junction.
[0060] In some embodiments, the electrodes can each independently
be spaced any suitable distance away from the junction, for
example, from about 0.1 inch to about 10 inches away from the
junction, from about 0.5 inch to about 5.0 inches away from the
junction, or from about 1.0 inch to about 3.0 inches away from the
junction. One or both of the electrodes can comprise a sleeve of
electrically conductive material, for example, a metal, surrounding
one or both of the conduits, and the method can comprise contacting
the sleeve with the lead/wire of a voltage source.
[0061] In some embodiments, the first conduit and the addition
conduit can have the same or different inner diameters and the same
or different outer diameters. In some embodiments, the addition
conduit can have a smaller inner diameter than the inner diameter
of the first conduit. In some embodiments, the inner diameter of
the addition conduit can be from about 10% to about 90% as large as
the inner diameter of the first conduit, for example, from about
25% to about 75% as large, or about 50% as large.
[0062] Referring now to the drawings, and according to various
embodiments, a mixture of nucleic acids, for example, a mixture
generated by a DNA library, can be diluted by a limiting dilution
procedure such that a concentration of a single molecule of
interest per a given volume of liquid can be obtained. Nucleic
acids obtained by any method can be diluted to a concentration such
that, for a given size of discrete volume, about one out of every
five discrete volumes can contain a single molecule, prior to
processing. When a sample is diluted to this extent, some discrete
volumes made from the diluted sample may not have any nucleic acid
molecules of interest at all, while others may have more than 1
molecule. For example, in some embodiments, about 20% of the
discrete volumes can contain a single molecule of interest,
although other concentrations can be used.
[0063] Greater details on obtaining such concentrations and
distributions of molecules per discrete volume, and uses for such
collections, 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.
[0064] According to various embodiments, as shown, for example, in
FIG. 1, a single molecule workflow can be provided wherein a
mixture of DNA 100, can be diluted such that at most about 40% of
the immiscible-fluid-discrete-volumes produced from a sample in the
process described below can comprise a single target nucleic acid
sequence. In various other embodiments, less than about 37% of the
immiscible-fluid-discrete-volumes produced can each comprise a
single target nucleic acid sequence. In other embodiments, at least
1% or more, 5% or more, 10% or more, or 20% or more can comprise a
single target nucleic acid sequence, for example, from about 5% to
about 40%, or from about 10% to about 20%.
[0065] One of skill in the art can appreciate how to prepare a
solution by limiting dilution. As illustrated in FIG. 1, after a
sample 100 is diluted by limiting dilution, a volume of sample 102
comprising a single nucleic acid molecule can be introduced into a
conduit 104, and passing a junction with an oil supply conduit,
forms an aqueous immiscible-fluid-discrete-volume 106. Not all
aqueous immiscible-fluid-discrete-volumes formed from the sample
will necessarily contain a single nucleic acid molecule of interest
there, and some, depicted as volumes 108, contain no molecules of
interest. In various embodiments, about 10% or less, about 20% or
less, or about 50% or less of the aqueous
immiscible-fluid-discrete-volumes can have one nucleic acid
molecule per given volume.
[0066] According to various embodiments shown in FIG. 2, a variable
input workflow can be provided wherein a mixture of nucleic acids
is supplied in a plate 200, for example, a mixture of genomic DNA
or cDNA, and oligonucleotide primers. Nucleic acids obtained by any
method can be provided in a conduit 202 at a concentration such
that each of the immiscible-fluid-discrete-volumes 204 produced
from the mixture comprise from about 10 to about 1000 copies of the
genomic DNA or cDNA. In various embodiments, the discrete volumes
can comprise from about 100 to about 500 copies of the genomic DNA
or cDNA, and in some embodiments each discrete volume can comprise
about 300 copies of genomic DNA or cDNA. In various embodiments,
the nucleic acid mixture can be removed, injected, or recovered
from one or more wells of plate 200.
[0067] Greater details on obtaining such concentrations and
distributions of molecules per discrete volume, and uses for such
collections, 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.
[0068] FIGS. 3A and 3B depict a system comprising a junction as
described herein and electrical circuitry configured to apply an
electric field at the junction. The circuitry comprises an
electrode sleeve surrounding the addition conduit and another
electrode contacting a T-intersection with which a first conduit
and the addition conduit are in fluid communication.
[0069] FIGS. 4 and 5 depict various schematic diagrams of two
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. In the schematic diagrams
of FIGS. 4 and 5, the slugOmeters and SOM's shown can be the same
as the various detectors shown in described in these referenced
applications.
[0070] FIGS. 6-8 depict the formulae of three respective surface
active agents that can be used in the compositions, systems, and
methods described herein. In some embodiments, any of the
surfactants shown in FIGS. 6-8 can be used in a concentration of
from about 0.1% by weight to about 10% by weight, for example, from
about 0.5% by weight to about 2.0% by weight, or about 1.0% by
weight, based on the weight of the oil or oil blend in which the
surfactant is added.
[0071] FIG. 9 depicts a system comprising a junction as described
herein and electrical circuitry configured to apply an electric
field at the junction. The circuitry comprises an electrode sleeve
surrounding the addition conduit and another electrode contacting a
T-intersection with which a first conduit and the addition conduit
are in fluid communication.
[0072] FIG. 10 depicts a system comprising a junction as described
herein and electrical circuitry configured to apply an electric
potential near the junction. The circuitry comprises an electrode
sleeve surrounding the addition conduit and another electrode
capacitively coupled to a T-intersection with which a first conduit
and the addition conduit are in fluid communication through, for
example, the air.
[0073] As shown in FIG. 11, the system exemplified can comprise a
first conduit 400 in fluid communication with a second conduit 402
at a junction 404. A composition comprising a non-fluorinated
polyalkylpolysiloxane oil 406 and discrete volumes of aqueous fluid
408, travels through first conduit 400 in the direction indicated.
The non-fluorinated polyalkylpolysiloxane oil and the aqueous fluid
are immiscible with one another and discrete volumes of aqueous
fluid 408 are spaced apart from one another. An addition fluid 410
in second conduit 402 can be added to a discrete volume of aqueous
fluid 412 at the junction 404. The enlarged discrete volumes of
aqueous fluid 414, comprising addition fluid 410, can then be made
to travel through first conduit 400, remaining non-coalesced with
one another. Electric circuitry such as that shown in FIGS. 3A and
3B can be used to provide an electric field at junction 404
sufficient to aid in the coalescence of addition fluid 410 to
discrete volumes of aqueous fluid 408 at junction 404.
[0074] The system can further comprise a pump 420 and a control
apparatus 422 configured to provide the addition fluid to the
discrete volumes of aqueous fluid. Pump 420 and apparatus 422 can
control the flow rate of addition fluid 410 so that a desired
amount of addition fluid 410 can be added to each discrete volume
of aqueous fluid 408 at junction 404.
[0075] Pump 420 and control unit 422 can be configured to pump
addition 410 continuously, in contrast to intermittently,
periodically, or on demand, into junction 404. Pump 420 and control
unit 422 can be configured to pump addition 410 intermittently into
junction 410, periodically into junction 410, or on demand into
junction 410. In some embodiments, a pump and control unit can
similarly be used to control the flow of non-fluorinated
polyalkylpolysiloxane oil 406 and discrete volumes of aqueous fluid
408 traveling through first conduit 400 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 406 and discrete volumes of aqueous fluid
408 traveling through first conduit 400 by pulling the composition
in the direction indicated.
[0076] In the embodiment shown in FIG. 12, a first conduit 430 and
a second conduit 432 are in fluid communication with each other at
a junction 434. A composition comprising a non-fluorinated
polyalkylpolysiloxane oil 436 and discrete volumes of aqueous fluid
438, travels in first conduit 430 in the direction indicated. As a
discrete volume of aqueous fluid 442 travels reaches junction 434,
a volume of aqueous fluid 440 can be removed from the discrete
volume 442 through second conduit 432. The reduced discrete volumes
of aqueous fluid 444 can then be made to continue to travel through
first conduit 430, and remain non-coalesced.
[0077] In the embodiment shown in FIG. 12, a pump 420 applies a
negative pressure to second conduit 432 causing the removal of
aqueous fluid 440 through the second conduit 432.
[0078] In the embodiment shown in FIG. 13, a system is provided
that comprises a first conduit 460, and a second conduit 462 in
fluid communication with the first conduit 460, at a junction 464.
A composition comprising a non-fluorinated polyalkylpolysiloxane
oil 466 and discrete volumes of an aqueous fluid 468, travels
through first conduit 460 in the indicated direction. As a discrete
volume of aqueous fluid travels through first conduit 460 and
through junction 464, additional oil 470 can be injected into the
composition through second conduit 462. The aqueous fluid 472 and
oil 470 are immiscible with one another. The discrete volume of
aqueous fluid 472 can be split into two smaller discrete volumes
474 and 476. The discrete volumes of aqueous fluid 474, 476, and
other previously split portions 478, remain non-coalesced as they
continue to travel through the first conduit.
[0079] In the embodiment shown in FIG. 14, the system comprises a
first conduit 500, and a second conduit 502 in fluid communication
with first conduit 500 at junction 504. The composition comprises a
non-fluorinated polyalkylpolysiloxane oil 506 and discrete volumes
of an aqueous fluid 508 traveling through the first conduit in the
indicated direction. Additional polyalkylpolysiloxane oil 510 is
added to the oil 506 between the discrete volumes 508 at the
junction 504. As a result, the system increases the spacing between
adjacent discrete volumes of aqueous fluid by providing a greater
amount of oil 514 in between adjacent discrete volumes. The
discrete volumes are indicated as 512 downstream of junction 504.
The discrete volumes of aqueous fluid 512 remain non-coalesced as
they continue to travel through the first conduit 500.
[0080] In the embodiment shown in FIG. 15, the system comprises a
first conduit 530, and a second conduit 532 in fluid communication
with the first conduit 530 at a junction 534. A composition
comprising a polyalkylpolysiloxane oil 536 and discrete volumes of
an aqueous fluid 538, which are immiscible with the oil, travels
through first conduit 530 in the indicated direction. At junction
534, a portion of a volume of polyalkylpolysiloxane oil 540 can be
removed between the adjacent discrete volumes of aqueous fluid 538
and 542 on either side of the volume of oil 540, at junction 534.
The system can accordingly be used to decrease the amount of oil
544, and thus the spacing, between adjacent discrete volumes of
aqueous fluid 542 and 546. As depicted, the discrete volumes of
aqueous fluid 546 remain non-coalesced as they continue to travel
through the first conduit 530.
[0081] 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.
* * * * *